Exploring the Articulation of Sentence-Stress among Teachers of English in Selected Nigerian Secondary Schools

A number of studies on Nigerian English intonation, of which sentence stress is a part, reveal that Nigerian English is devoid of accentuation; it is generally spoken with tone. Even at that, none of these studies has analyzed how teachers of English in Nigeria articulate or utilize sentence stress in speech, whether consciously or unconsciously. This present study focuses, therefore, on the performance of secondary school English teachers in the use of sentence stress for effective communication. Analysis of 24 (12 short and 12 long) elicited English sentences uttered by 32 secondary school English teachers in Lagos State of Nigeria reveal a performance of only 27% correct accentuation and 73% incorrect accentuation. The study concludes that secondary school teachers of English in Nigeria have not adequately mastered the art of accenting the right words in sentences to accurately generate the intended meaning. The study recommends that intensive trainings be organized for teachers of English, thereby creating awareness of the need to treat sentence stress not only as a mere English Language classroom topic, but also as an effective tool of oral communication beyond the shores of Nigeria.

(c) to examine ways to enhance secondary school English teachers' performance in sentence stress articulation.

Sentence Stress: Accent, Emphasis, Contrast and Focus
Accent as used in this present study differs from Yule's (2010, p. 240) conceptualization of the term as "aspects of pronunciation that identify where an individual speaker is from, regionally or socially".
Rather, it is limited to that word that the speaker expends more force or energy on in a bid to attract or focus the listener's attention on it for the overall interpretation of its significance to the encoded meaning. The decision to accent particular words in a sentence rather than others depends on the context of the message and the attitude of the speaker towards some aspect of the message (Sabater, 1991). Intuitively, pitch accents in English indicate that the speaker means to stress the importance of the words they appear on (Gussenhoven, 2008). Thus, sentence stress can be described as the relative degree of force given to the different words in a sentence (Clark & Yallop, 2000;Bian, 2013), especially in order to make the words stand out, thereby signifying their importance in the sentence. Levis and Levis (2011) note that the focus for accentuation usually, should be on the last content word in a sentence. However, it does not necessarily belong on the last word when the context contains contrast. Even the content words, according to Bian, are not of the same significance to the meaning of the syntactic structure. "The relative importance of words, therefore, provides a basis for determining their relative stress" (Bian, 2013, p. 4). Bian notes in other words that a content word may be unstressed when it is less important. By the same token, Aremo (2012, p. 99) points out that, although content words are normally accented in a sentence, any word at all may be given extra strong stress for the purpose of emphasizing some points or for contrasting the word with some other words the listener might wrongly assume was used or intended. Thus, accent in an utterance cannot be separated from the information a listener deduces as the intended message. Aremo notes further that a grammatical word such as a pronoun, a preposition, a conjunction or an interjection can sometimes be accented for the purpose of emphasizing some point or contrasting the word with some other word the listener might wrongly think the speaker had wanted to use. This extra strong stress is indeed what is commonly referred to as emphatic or contrastive stress, depending on what is considered the exact purpose it is made to serve. A function word is thus accented or focused, only when it calls attention to the meaning it conveys (Kupier & Allan, 1996); a presupposition that sentence stress or accentuation can also be regarded as focus (Ladd, 1980;Gussenhoven, 1994;Levis & Levis, 2011;Na, Yuan, & Bin, 2012).
Because the researchers set out to investigate the level of teachers' competence in the mastery of the art of sentence stress within the ambit of the elicited data for the study, both content and function words are accented at the initial, medial or final positions of sentences, in accordance with how important they are to the interpretation of the sentences under study. By maximizing the mobility of accent, in what appears to be the same utterance, Kreidler, (1997) posits that a speaker can create "differences in focus, www.scholink.org/ojs/index.php/selt Studies in English Language Teaching Vol. 8, No. 3, 2020 169 Published by SCHOLINK INC. which are subtle differences of meaning" (p. 105). Gussenhoven (1994) posits that English uses pitch accents to mark focus, with special emphasis on the phenomenon of "focus projection" (cf. Levis & Levis, 2011;Na, Yuan, & Bin, 2012). The domain of focus projection is referred to as the "focus domain"; a constituent that can have its focus marked with a single pitch accent, such as focused Argument, Modifier, or Argument-Modifier combination (Gussenhoven, 1994). However, the constituent on which the pitch accent falls is taken to be the focus of the message in the sentence. English is noted to have 'restricted' focus projection, i.e. from the argument to its predicate and not extended focus projection which allows focus to be projected to much large constituents. Restricted focus projection is used to refute the assumption that full focus version of a sentence is equivalent to a narrow version with the focus on the last pitch accented word. Na et al.'s (2012) concepts of broad and narrow focus relate closely with Gussenhoven's (1994) restricted focus projection and extended focus projection. Ladd (1980) and Na et al. (2012) Kreidler's (1997) model which forms the framework for the study (see Sections 3.1 and 4).

Cross-linguistic Influence of Sentence Stress
English language is a stress-timed language. Hence, the proper use of English word stress and sentence stress by L2 speakers, especially those whose L1 are tonal or syllable-timed, poses great challenge (e.g., Fajobi, 1998;Faleye, 2016;Melefa, 2018;Melefa & Amoniyan, 2019). It has been observed that in Nigerian English, tone is often taken as a correlate of stress, while intonation is devoid of accentuation (Fajobi, 2013). In fact, the common practice, in an attempt to accent, is the "tonologization of English stresses/syllables" (Fajobi, 2008, p. 230). In other words, Nigerian English is a tonal variety of English; it has been generally reported to be spoken with tone rather than stress (e.g., Wells, 1982;Gut & Milde, 2002;Fajobi 2008Fajobi , 2013Gussenhoven & Udofot, 2010). Therefore, there may be some sociophonological and cross-linguistic influence of L1 on L2 in the realisation of English sentence stress by L2 speakers whose linguistic backgrounds are syllable-timed as is the case in Nigerian English. Hickey (2004, p. 529)  ii) The expression gains other meanings; and iii) A person thinks in native language and expresses in some other one. Wayland et al. (2006) observe that there is evidence of transfer of L1 stress patterns into English by Thailand speakers of English. Thai, the standard language in Thailand, unlike English, is a tone language. Thus, Wayland et al. (ibid) submitted that the tendency of transferring the knowledge of tone into English intonation or sentence stress articulation is very high. In fact, non-native speakers are said to be at loss when faced with the task of using intonation in their English speech or interpreting it (Atoye, 2005 at different positions. Using the example of possible English and Spanish responses to the question "Who eats mangoes?", Dominguez observes that while English gives an SVO structure (in an active sentence) with the maximum prominence being on the stressed syllable of the subject, Spanish has a VOS structure; hence, prominence falls on the last element. As a consequence, speakers of English from these two backgrounds will run into the problem of intelligibility because the Spanish-English speaker will inadvertently shift stress from its normal position. In what is similar to Dominguez's (2013) study, Melefa and Amoniyan (2019)  English is the Fundamental Frequency contour and it is usually placed on the last word in the sentence.
The choice of rise and fall is made between it. The present researchers are interested in examining the extent to which ESL teachers in Nigeria are able to correctly deploy sentence stress (and its acoustic correlates) as a "compact tool" for information dissemination in formal classroom environment.

Theoretical Framework
Kreidler's Tonicity Model forms the theoretical framework for this study. Tonicity, according to Kreidler (1997), is the "position of the accented word within a tone unit". The word accented in a sentence serves as the focus of the message. Therefore, by maximising the mobility of accent, in what appears to be the same utterance, a speaker can create "differences in focus, which are subtle differences of meaning" (Kreidler 1997, p. 105). Although, function words are naturally unstressed and weak, any word within a sentence can be accented and then it becomes strong. Every tone unit has one accented word, which is the most informative word referred to as the nucleus of the tone unit. Usually, the nucleus occurs at or near the end of the tone unit. However, an utterance can have different tonicity (nuclear word) in different contexts; thus, focusing the listener's attention on the speaker's intended message. Once the nucleus of a sentence is identified, the remaining part (onset and/or coda) is The semantic implication of each structure differs. In (a), the message obtainable is that the speaker's buying of houses has taken place at the moment, not necessarily a thing of the distant past. In (b) the speaker is the one projected in contrast to any other person that may come to the mind of the listener. In (c) houses (and not cars) constitute the main focus. Hence, for every element accented, there are other applicable alternatives, against which the listener measures the word accented to arrive at the speaker's meaning. Accentuation, therefore, has some form of paradigmatic implication. However, when the speaker's nucleus within the sentence does not represent his intended message and where the listener takes such to be significant for meaning, there is the possibility of a breakdown in communication.

The Subjects
The respondents for this study are 32 English teachers, purposively selected across four local government areas in Lagos State: Eti Osa, Ikeja, Kosofe and Mushin. These local governments were chosen to be representative of the urban areas (Eti Osa and Ikeja), semi-rural and rural (Kosofe and Mushin) areas of Lagos State. This was done in order to have a more vivid picture of what is obtainable in different parts of Lagos State. Readers need to know that Lagos State used to be the capital of Nigeria for decades after the nation attained independence in 1960. We therefore believe that, since people from different parts of the nation live in it, subjects drawn from the state could be representative of the Nigerian populace.

Test Items, Test Design and Administration
Participants were asked to react to a structured three-section questionnaire. The first part of the questionnaire was designed to elicit demographic information, the second part examined the informants' level of awareness of the significance of sentence stress, while the third part consisted 24 sentences read aloud by the 32 respondents and recorded (see the test items in Section 4). A total of 768 tokens were generated and subjected to acoustic analysis, using PRAAT, in order to determine how effectively the informants were able to use sentence stress to communicate as teachers in the classroom. The sentences in the questionnaire are in two categories: short sentences portraying different intensions of the speaker and long sentences in a dialogue, involving a teacher and a student.

Analysis and Findings
The data was analysed using Kreidler's (1997) Tonicity Model, with emphasis placed on the tone unit structure (the onset, nucleus and the coda). The word signifying the intended message in the sentence is taken to be the nucleus, while elements before and after it are regarded as the onset and coda, respectively. Also, the performances of the respondents in the experimental sentences were statistically represented, using descriptive and inferential statistics (frequency tables, simple percentages and figures The accented word that portrays youthfulness and serves as the nucleus in Ti1 is childish. Thus, the tone unit structure for the sentence is given as:

Onset Nucleus Coda
Your attitude was childish ________ The sentence has an onset and a nucleus, with no coda. However, out of the 32 informants tested, 12 (37.5%) accented the right word, having accented the appropriate word and given the sentence its proper onset-nucleus-ɸ structure. 20 (62.5%) respondents missed it. 16 of them accented attitude and 1 of them accented was; thus, making the sentence to assume an onset-nucleus-coda pattern. The remaining 3 of the respondents accented Your and produced the pattern ɸ-nucleus-coda. Figure 1 below shows, acoustically, an example of the performance of informant (Inf) 2 in test item 1. The pitch trace for the informant starts at 158.8Hz, reaches its peak at 181.5Hz (the highest) on the word attitude and ends at 108.2Hz. This shows that rather than accent childish, he accented attitude. The accented word and nucleus of this utterance is young. The tone unit structure for the utterance is:

Onset Nucleus Coda
It feels great to be young ________ Ti2 has an onset and a nucleus with no coda. However, out of the 32 respondents tested, only 2 (6%) got it right by accenting the appropriate word and producing the onset-nucleus-ɸ structure. 30 (94%) respondents missed it. 3 of them accented the preposition to, 3 others accented great, while 21 of them accented feel, all realizing structure "onset-nucleus-coda". The remaining 3 accented it, realizing the structure ɸ-nucleus-coda. In Figure 2 below, the pitch trace for Inf4's rendition of the utterance starts at 256.3Hz on it, rises to 346.6Hz on feels, which is the nucleus and then falls at 174.8Hz on the last word.

Respondents' Performance in Ti3: He was Sent to a Juvenile Home
The word juvenile is accented and thus serves as the nucleus of the utterance. The tone unit structure is represented as:

Onset Nucleus Coda
He was sent to a juvenile home The sentence has an onset, a nucleus and a coda. Yet, only 5 (16%) out of the 32 respondents got it right, as they realized the onset-nucleus-coda structure and accented the appropriate word. 27 (84%) other respondents missed it. 3 of them accented the word he and arrived at a ɸ-nucleus-coda structure.
The remaining realized an onset-nucleus-coda pattern, but missed the accented component; 21 of them accented sent, 2 accented to and 1 accented was. Figure 3 shows an incorrect articulation of the nucleus by Inf8 whose fundamental frequency (F 0 ) or pitch is highest on the word sent rather than on juvenile.
The pitch trace for Inf8's performance begins at 138.7Hz, rises to 202Hz on the word sent and falls at 122.2Hz, as represented below:  The nucleus to be accented in the utterance is youths. The tone unit of the utterance is structurally represented as:

Onset Nucleus Coda
The youths are protesting Ti4 has an onset, a nucleus and a coda. Out of the 32 tested respondents, 20 (62.5%) got it right. They realized the appropriate onset-nucleus-coda structure and accented the correct word. 12 (37.5%) of the respondents missed it. 9 of them accented the word protesting, realizing the onset-nucleus structure.
The remaining 3 accented are. Figure 4 below represents the pitch trace for Inf9, which starts at 184.6Hz, rises to 348.2Hz on the word protesting and falls at 163.6Hz. She did not accent the correct word. The accented word and nucleus of the utterance in Section 4.5 above is must and the tone unit structure for the utterance is:

Onset Nucleus Coda
You must be ready for the task Ti5 has an onset, a nucleus and a coda. However, only 11 (34%) respondents out of 32 tested, placed the accent on the proper word and realized an onset-nucleus-coda structure. 21 (66%) others accented wrong words. 1 respondent accented you and realized a ɸ-nucleus-coda pattern. 5 respondents accented task and arrived at an onset-nucleus-ɸ pattern. 1 respondent accented for and 1 other respondent accented be respectively. 13 others accented ready, all realizing the onset-nucleus-coda pattern but missing out on the correct stress placement. The pitch trace for Inf10 starts at 120.9Hz on the word must, rises to 198.8Hz and falls at 134.4Hz, as depicted in Figure 5:

Respondents' Performance in Ti7: We Demand That You Quit
The word that is accented to express compulsion and serve as the nucleus in this utterance is demand.
The tone unit is structurally represented as:

Onset Nucleus Coda
We demand that you quit The tone unit consists of the onset, nucleus and coda. 18 (56%) respondents out of 32 realized the proper stress pattern and structure of the sentence; onset nucleus coda. 14 (44%) others missed it. 10 respondents accented quit and realized an onset-nucleus-ɸ pattern. 1 respondent accented we and derived a ɸ-nucleus-coda structure; 2 respondents accented that, while 1 other respondent accented you. For Inf13, as shown in Figure 7 below, the pitch trace on the wrongly accented quit starts from 140.6Hz, rises to 227.3Hz and ends on 93.99Hz.

Respondents' Performance in Ti8: We have to Dance Well
The phrase "have to" is accented and serves as the nucleus of the utterance. The structure of this tone unit is:

Onset Nucleus Coda
We have to dance well The utterance therefore consists of an onset, a nucleus and a coda. Out of 32 respondents, 22 (69%) accented the proper element and also correctly realized an onset-nucleus-coda structure. The remaining 10 (31%) respondents accented the wrong elements in the sentence. 5 of them accented well and realized an onset-nucleus-ɸ pattern. 2 respondents accented we and derived a ɸ-nucleus-coda structure.
2 other respondents accented to, while 1 accented dance. The pitch trace for Inf14, as represented in  The test items in section 4.9 through 4.12 belong to Group C of Category 1. The speaker's intension here is to portray inclusion/addition. An utterance-by-utterance description of the test items is provided below, starting with the test item in Section 4.9.
The conjunction and is the nucleus of Ti9; it is accented to express inclusion/addition. It can be structurally represented as:

Onset Nucleus Coda
Mary and John were there The utterance consists of the onset, nucleus and coda. However, only 3 (9%) out of the 32 respondents tested got it correctly. 29 (91%) others missed it. As many as 26 respondents accented Mary and realized a ɸ-nucleus-coda structure, while 3 other respondents accented John. Figure 9 below shows Inf15's pitch trace, which starts from 202.5Hz, rises to 333.5Hz on the wrong word Mary, and falls on 153.6Hz.

Respondents' Performance in Ti10: He Walks with His Dog.
The word accented in this utterance is with. It can be represented structurally as:

Onset Nucleus Coda
He walks with his dog Thus, Ti10 maintains an onset-nucleus-coda structure. Out of 32 respondents tested, only 6 (19%) got it correctly, while 26 (81%) produced the sentence with the wrong stress placement. 18 respondents accented walks, while 2 others accented his. 3 respondents accented he and derived a ɸ-nucleus-coda pattern. 3 other respondents accented dog and realized an onset-nucleus-ɸ structure. The pitch trace for Inf16 in Figure 10 starts from 206.6Hz, rises to 231.3Hz on the word walks and ends at 155Hz, as represented below: The word also is accented to portray inclusion/addition. The structure of the tone unit is therefore represented as:

Onset Nucleus Coda
We sent a card also __________ The utterance consists of the onset and nucleus only. However, only 5 (16%) respondents got the proper accentuation and structure. 27 (84%) others accented something else and realized a completely different structure. 23 of them accented sent, 3 accented card, while 1 accented a, all deriving an onset-nucleus-coda structure. Figure 11 shows the rendition by an informant, who accented the wrong word. The pitch trace for Inf20 starts at 198.6Hz, rises to 208.5Hz on the word sent and falls on 159.9Hz, as represented below:

Respondents' Performance in Ti12: We are in Your Group
The word in is accented and considered the nucleus of the utterance. The structure of the tone unit is:

Onset Nucleus Coda
We are in your group The onset, nucleus and coda are adequately represented in the utterance. 8 (25%) out of 32 respondents got the stress placement and the onset-nucleus-coda structure right. 24 (75%) others missed it. 12 of them accented group and realized an onset-nucleus-ɸ pattern. 7 of the respondents accented we and altered the original pattern to derive a ɸ-nucleus-coda structure. The remaining 5 accented your. Figure   12 shows the pitch trace for Inf21, which starts from 222.6Hz, reaches its peak at 252.1Hz on the word we and drops on 203.9Hz.

Respondents' Performance in Ti13
Test items in section 4.13 to 4.15 belong to Sub-category 2.i under Category 2. The dialogue is a question-and-answer session between a teacher and a student. A word in each of the student's responses negates the impression of the teacher. The word is accented and given a structural tone unit representation.

Test item 13 (Ti13):
Teacher: Was it a very unpleasant day for Pat, the bride-to-be?

Student:
It was a very pleasant day for Pat, the bride-to-be.
The word pleasant in the student's response negates the teacher's impression and is thus accented. It can be structurally represented as:

Onset Nucleus Coda
It was a very pleasant day for Pat, the bride-to-be.
The onset, nucleus and coda are represented in the utterance. Out of the 32 respondents, 7 (22%) got the stress placement correctly and realized an onset-nucleus-coda structure. 25 (78%) others placed the stress wrongly and altered the structure in few cases. 2 of the respondents accented it and derived a ɸ-nucleus-coda pattern. 1 respondent accented for, 1 accented Pat, 1 accented to, 1 accented a, 1 other accented day. 5 accented was, while the remaining 13 accented very, all retaining the original sentence structure. Figure 13 below portrays the pitch trace for Inf22, which starts from 119.4Hz, rises to 206.3Hz on the word pleasant and falls on 103Hz.

Respondents' Performance in Ti14
Teacher: Was Pat indifferent about her facial blemish from chickenpox?

Student:
Pat was bothered about her facial blemish from chickenpox.
The word bothered negates indifferent, which is the teacher's impression. Thus, bothered is accented and serves as the nucleus of the utterance. The structural representation is:

Onset Nucleus Coda
Pat was bothered about her facial blemish from chickenpox respondents accented the wrong words and some of them altered the structure of the item. 17 of them accented Pat, realising a ɸ-nucleus-coda structure. 2 accented chickenpox and derived an onset-nucleus-ɸ pattern. 4 accented facial, 2 accented her and 1 accented from. For Inf23, as shown in Figure 14 below, the pitch trace starts at 182.2Hz, reaches its peak at 216.9Hz on bothered and falls at 102.2Hz.

Respondents' Performance in Ti15
Teacher: Did Ben consider her to be ugly?

Student:
Ben considered her to be charming.
The word charming is accented to negate the speaker's impression. Therefore, it serves as the nucleus of the utterance. It can be given the following structural representation:

Onset Nucleus Coda
Ben considered her to be charming ___________ Ti15 has an onset-nucleus-ɸ pattern. Out of the 32 respondents tested, 7 (22%) got the correct stress pattern and structure, while 25 (78%) missed it. 13 of them accented Ben and derived a ɸ-nucleus-coda structure. 7 accented considered, 2 accented to, 1 accented be, 1 accented Pat, while 1 other person accented her. For Inf1, as represented in Figure 15, the pitch trace starts at 117.3Hz, rises to 176.4Hz on the word Ben and falls at 89.32Hz.

Respondents' Performance in Ti16
Test items in section 4.16 through 4.21 belong to Sub-category 2.ii of Category 2. Here, a word in each of the student's questions negates the teacher's impression. Thus, the definite question-word is accented, while each utterance is structurally represented.

Test Item 16 (Ti16):
Teacher: Ben called this morning to say that he would be at the wedding in his most unusual form.
Student: Did Ben call this morning to say that he would be at the wedding in his most usual form?
The nucleus and accented word in the student's question is usual. It is structurally represented as:

Onset Nucleus Coda
Did Ben call... usual form Ti16 consists of the onset, nucleus and a coda. Out of the 32 respondents tested, none (0%) was able to get it right. All 32 (100%) respondents placed stress on the wrong words and some altered the structure of the sentence. 17 respondents accented Ben, 2 accented call, 1 respondent accented at, 1 accented say, 1 accented that, 1 other accented wedding, 1 accented to, 1 accented he. 7 other respondents accented form and gave the sentence an onset-nucleus-ɸ coda pattern. The pitch trace for Inf3 in the production of Ti16, as shown in Figure 16, starts on Ben from 176.4Hz rises to 359.2Hz and falls at 172.2Hz.

Respondents' Performance in Ti17
Teacher: Pat thought Ben was full of surprises.

Student: Did Pat think Ben was predictable?
Predictable is the nucleus and the accented word in the student's question. It is thus structurally represented as:

Onset Nucleus Coda
Did Pat think Ben was predictable __________?
The coda is absent in the utterance, while the onset and nucleus are represented. 15 (47%) respondents out of 32 accented the correct word and realized the proper onset-nucleus-ɸ structure. 17 (53%) other respondents missed it. 14 of them accented Pat, 2 accented was, while 1 accented think; all realizing an onset-nucleus-coda pattern. Figure 17 below is the pitch trace for Inf29's performance, which starts from 142.1Hz and reaches its peak at 294.9Hz on predictable. The accented word/nucleus happens to be the last element in the sentence, which is a question; hence, the rise in the pitch trace of the respondent's production of the word.

Respondents' Performance in Ti18
Teacher: Pat was very eager to see her Mr. Charm.

Student: Was Pat very reluctant to see her Mr. Charm?
The word reluctant in the student's question negates the teacher's impression and is thus the nucleus of the utterance. The tone unit structure for the utterance is:

Onset Nucleus Coda
Was Pat very reluctant to see her Mr. Charm Ti18 thus has an onset-nucleus-coda structure. Out of the 32 respondents tested, only 3 (9%) got it correctly. 29 (91%) other respondents had a wrong stress placement, while some altered the original structure of the sentence. 11 of them accented Pat, 9 accented charm, 5 accented see, 1 accented her, 1 accented Mr. The 2 others accented was and thus gave the sentence a ɸ-nucleus-coda structure. For Inf30, the pitch trace, as represented in Figure 18, starts from 191.2Hz, rises to 261.3Hz on Pat and falls at 257.8Hz.

Respondents' Performance in Ti19
Teacher: Pat became surprised to find her seventy-year-old next-door neighbour waiting as the groom.
Student: Did Pat become unsurprised to find her seventy-year-old next-door neighbour waiting as the groom? The word accented in the above question is unsurprised and it is also the nucleus. The structural representation of the utterance is:

Onset Nucleus Coda
Did Pat become unsurprised to find her...
The onset, nucleus and coda are present in the utterance. Out of the 32 respondents tested, 6 (19%) got the proper stress placement and the onset-nucleus-coda structure of the sentence. 26 (81%) others did not get the correct stress, while one of them altered the structure. 10 of the respondents accented Pat, 4 accented seventy, 4 others accented groom, 2 accented become, 2 accented old, 1 respondent accented to, 1 accented waiting, while 1 also accented the. 1 respondent accented did and realized a ɸ-nucleus-coda structure. For Inf25, the pitch trace starts at 236.7Hz, reaches its peak at 323.8Hz on the word Pat and falls at 297.4Hz, as shown in Figure 19 below:

Respondents' Performance in Ti20
Teacher: She had never talked to him all their days as neighbours.

Student:
Had she ever talked to him all their days as neighbours?
The word ever serves as the nucleus, as well as the word accented to negate the teacher's impression.
Its structural representation is:

Onset Nucleus Coda
Had she ever talked to him all their days as neighbours The onset, nucleus and coda are present in Ti20. However, only 1 (3%) of the 32 respondents got the correct stress pattern and structure of the sentence. 31 (97%) other respondents missed it and altered the structure in some instances. 19 of them accented she, 2 accented days, 2 accented as, 1 accented him, 1 accented had and 1 respondent accented to. 5 others accented neighbours and made the sentence to assume the structure onset-nucleus-ɸ. Figure 20 shows the pitch trace for Inf12, which starts from 110.2Hz, rises to 206.9Hz on the word she and falls at 128.7Hz.

Respondents' Performance in Ti21
Teacher: Pat was more amazed to hear him talk exactly like Ben.
Student: Was Pat more amazed to hear him laugh exactly like Ben?
Laugh is both the nucleus and the accented word that negates the teacher's impression in Ti21. The tone unit structure of the utterance is thus:

Onset Nucleus Coda
Was Pat more amazed to hear him laugh exactly like Ben Although, Ti21 has an onset, a nucleus and a coda, only 1 (3%) of the 32 respondents got the correct stress pattern and structure of the sentence. 31 (97%) other respondents missed it and altered the structure in some instances. 19 of the respondents accented Pat, 3 accented amazed,1 accented more, 1 accented exactly, 1 accented she, and 1 of them accented to. The remaining 5 accented Ben, thus realized an onset-nucleus-ɸ structure. The pitch trace for Inf17 starts at 106.3Hz, rises to 219.3Hz on the word Ben and falls at 188Hz, as represented in Figure 21 below:

Respondents' Performance in Ti22
Test items in section 4.22 through 4.24 belong to Sub-category 2.iii of Category 2. In this part, a certain word in each of the student's questions projects the teacher's impression. The definite question-words concerned are accented and structurally represented below.

Test Item 22 (Ti22):
Teacher: Pat collapsed and could faintly hear her chief bride's maid's voice calling her to wake up.

Student:
Pat collapsed and could faintly hear whose voice calling her to wake up?  Vol. 8, No. 3, 2020 186 Published by SCHOLINK INC.
The word whose in the student's question is both the accented word that portrays the teacher's impression and the nucleus. The structural representation of the utterance is:

Onset Nucleus Coda
Pat collapsed... whose voice calling her to wake up?
Ti22 is made up of the onset, nucleus and coda. 8 (25%) respondents out of the 32 tested produced the sentence with the correct stress placement and structure. 24 (75%) other respondents did otherwise. 12 of them accented Pat and realized a ɸ-nucleus-coda structure. 3 accented up, 3 accented faintly, 2 accented collapsed, 2 accented calling, 1 accented and, while 1 also accented she. For Inf5, as portrayed in Figure 22, the pitch trace starts from 254.4Hz, rises to 263.3Hz on faintly and falls at 147.7Hz.

Respondents' Performance in Ti23
Teacher: With the repeated knock at the door and the alarm blaring to announce it was 6 a.m., Pat dashed out of bed panting.

Student:
With the repeated knock at the door and the alarm blaring to announce it was 6am, who dashed out of bed panting?
The word who in the student's question is the nucleus and the accented word that reflects the teacher's impression. It is structurally represented as:

Onset Nucleus Coda
With the repeated knock... who dashed out of bed panting The onset, nucleus and coda are present in Ti23. Out of the 32 respondents tested, 12 (37.5%) produced the sentence with the appropriate stress placement and structure, while the remaining 20 (62.5%) respondents did not do that exactly. 10 of them accented repeated, 3 accented 6a.m, 1 accented and, 1 accented door, 1 accented at, 1 accented up, and 1 accented dashed. The remaining 2 respondents accented panting and derived an onset-nucleus-ɸ structure for the sentence. For Inf18, as shown in Figure 23, the pitch trace starts from 173.3Hz, rises to 343.1Hz on the word who and falls at 113.9Hz.

Respondents' Performance in Ti24
Teacher: She ran to the mirror to examine if her face truly had blemishes from chickenpox.
Student: She ran to the mirror to examine if what truly had blemishes from chickenpox?
In the student's question above, the word what is the nucleus, as well as the accented word, portraying the teacher's impression. The structural representation of this tone unit is thus:

Onset Nucleus Coda
She ran to the mirror... what truly had blemishes from chickenpox?
Ti24 consists of the onset, the nucleus and the coda. Out of 32 respondents tested, only 6 (19%) were able to produce the correct structure and place the stress on the right word. 26 (81%) other respondents did not get it right. 13 of the respondents accented ran, 3 of them accented if, 2 of them accented from, 2 accented truly, 1 accented had, 1 accented Ben, 1 accented to and 1 accented examined. 1 of the respondents accented she and realized a ɸ-nucleus-coda structure, while 1 other accented chickenpox and derived an onset-nucleus-ɸ pattern. For Inf19, the pitch trace starts from 147.4Hz, reaches its peak at 228.4Hz on the word if and falls at 109.6Hz, as shown in Figure 24 below:  in sentences with the words articulated in the same, in spite of the explicit instruction and explanations provided by the researchers as guide. Their performance in short sentences was not any better than what was obtained in the long sentences. Thus, they simply accented any part of a sentence as deemed fit, not as appropriate to the message encoded in the sentence. Other interesting findings from the teachers' performance in sentence-stress articulation experiment carried out in this study include the following, among others: (i) Respondents' inability to communicate meaning when sentence stress is to be used as the tool of communication. Although, a good number of the respondents claim to stress words when they interact with their students, findings from the analysis prove that sentence stress is quite alien to them. Hence their averred attempt must be a misuse of sentence-stress.
(iii) Wrong feedback: A listener who by chance considers the accented word(s) in a sentence to be significant for meaning gets a different message and gives a wrong/different feedback from what is expected.
(iv) Listeners, especially learners, are often indifferent or react negatively to any attempt to stress words, as gathered in the questionnaire. Some listeners who take it well mostly consider it as a demonstration of expertise not as a tool of communication.
(v) Justice is not done to the teaching of stress because the teachers themselves are yet to understand the workings of this skill in communication.
(vi) Prolonged conversation: Cases of prolonged conversation due to the employment of more words to make up for inadequacies in the use of stress to communicate, were also evident in the respondents' performance.
Implication of the above include the fact that, sentence-stress articulation as part of the teaching contents of the English language in Nigerian secondary schools is yet to receive adequate attention in practice. Curriculum planners and executors need to pay more attention to not only the teaching, learning and practice of this aspect of spoken language, but also the prosody generally.

Conclusion
In this study, the analyses carried out reveal that sentence-stress is a significant tool for communication in English. The word accented in a sentence is significant for meaning. Hence, if the sentence stress is properly articulated, the speaker's meaning equals the listener's. However, a misuse of sentence stress brings about conflicting meanings from both ends of production and reception, as the message communicated will not be understood.
Sadly, acclaimed experts who are expected to be adept in the use of sentence stress have been discovered to have shallow knowledge in the workings of the same. Hardly was there any teacher, among those tested, whose performance was above average. English teachers who impart knowledge to learners are expected to know and be proficient in the articulation of sentence stress, being an aspect of the subject that they teach and a key tool of communication in the language of instruction.
Since the teachers are not conversant with the use of sentence stress in communication, the chance of instructing learners, some of who will in turn become instructors, is slim. Hence the significance of sentence stress stands the risk of being swept under the carpet, while communication continues to be an arduous task to perform.
However, organization of national and international intensive trainings for teachers as well as introducing them, at the secondary school level, to speech analyzers that can help them to personally assess their performances in accentuation exercise will go a long way to improve the teachers' quality.
Keeping abreast with developments in English prosody, getting acquainted with e-learning and listening to BBC and other RP sources can also enhance the teachers' performance in sentence stress articulation.