Theory of phonetics

to structure a text. It is an organizing mechanism, it delimitates texts into smaller units, i.e. phonetic passages, phrases and intonation groups, and on the other hand it integrates these smaller constituents forming a complete text. The organization of connections between phrases manifests how one idea leads on from another.

t o differentiate the meaning of textual units (i.e. intonation groups, phrases and sometimes phonetic passages) of the same grammatical structure and the same lexical composition, which is the distinctive or phonological function. The distinctive function of intonation is realized in the opposition of the same word sequences which differ in certain parameters of the intonation pattern. Intonation patterns make their distinctive contribution at intonation group, phrase and text levels, e.g.

\ Call me if Nelly 'arrives in the \evening. (no one but Nelly is expected to arrive)
\Call me if \Nelly ׀arrives in the ׀evening. (a few people are expected to arrive)

6. 
   to characterize a particular style or variety of oral speech which may be called the stylistic function.
   

7. to transmit feelings, emotions and modality. It helps to express the speaker’s inner state: nervous (oftener makes pauses, ending elision, shift of rhythm, half crying, etc), indignant (loud voice + high pitch, screams, etc.), overwhelming with emotions (Fall-Rise, accidental rise, etc) in oral speech. The speaker must be particularly careful about the attitudes and emotions he expresses since the hearer is frequently more interested in the speaker’s attitude or feeling than in his words – grammatically or stylistically correct / incorrect, nicely, etc.
\What? – with Low Fall it sounds detached, suppressing, categorical, sometimes even hostile.
>What? With Low-Rise it expresses some shade of emotional meaning “to the point”, interested, sympathetic, friendly, concerned.
8. to tie the major parts together within the phrase and to tie phrases together within the text (grammatical function) – showing, in the process, what things belong more closely together than the others, where the divisions come, what is subordinated to what, and if one is telling, asking, commanding or exclaiming.
Intonation also aims to show which information is new for the listener. In oral
English the smallest piece of intonation is associated with an intonation group (a unit of intonation containing the nucleus). There is no exact match between punctuation in writing and intonation group in speech. Speech is more variable in its structuring of information than in writing. Cutting up the speech into intonation groups depends on such things as speed at which you are speaking, what emphasis you want to give to the parts of the message, and the length of grammatical units. A single phrase may have just one intonation group; but when the length of the phrase is beyond a certain point, it is difficult not to split it into two or more separate pieces of information, i.e.
The girl declared we could leave our suitcases here.
The girl declared | we could leave our suitcases at the hotel.
The girl declared | we could leave our suitcases | at the hotel situated just round the corner.
Accentual systems involve more than singling out important words by accenting them. Intonation group or phrase accentuation focuses on the nucleus of these intonation units. The nucleus marks the focus of information or the part of the pattern to which the speaker especially draws the hearer’s attention. The focus of information may be concentrated on a single word or spread over a group of words. Even words like personal pronouns, prepositions and auxiliaries, which are not normally stressed at all, can receive nuclear stress for special contrastive purposes:
This isn’t \your pen, it’s \ mine.
We can roughly divide the given information into:

retrievable (or the theme) It suggests information which has already been mentioned or alluded to. Retrieved information can be delivered from: 1) verbal context; 2) situational context.

new (or the rheme) New information is obviously the most important in a message, it receives the information focus

It is 8 o’clock. The secretary must be coming.
“The secretary” may be considered to be the theme, “must be coming” – the rheme.
But if we accent the word with Low Fall it may function as the rheme.
The \secretary must be coming.
Information may be considered to be main and subsidiary from the point of view of its importance for the listener e.g.
We met your husband there at five.
main subsidiary
Any section of the intonation pattern can perform the distinctive function being phonological units. These units form a complex system of intonemes, tonemes, accentemes, chronemes, etc. These phonological units like phonemes consist of a number of allotones, which are mutually non-distinctive. The principal allotone is realized in the nucleus alone. The subsidiary allotones are realized not only in the nucleus, but also in the pre-head and in the tail if any, e.g.