Three principal functions of sentence stress in English

In a sentence or an intonation group some of the words are of greater importance than the others. This largely depends on the situation or context. Words which provide most of the information are brought out in speech by means of sentence-stress. Thus sentence stress is a special prominence given to one or more words according to their importance in a sentence.

1) The main function of SS is TO SINGLE OUT THE COMMUNICATIVE CENTRE of the sen-ce which introduces new information. The prominence is realized by variations of pitch, force, length and quality. The stressed words are pronounced more distinctly. The most prominent part of a sentence is the last stressed word which takes the nuclear tone. It indicates the nucleus of the communicative centre. The second in weight is the first stressed word which often has the highest pitch and is loud.

Nominal words are usually accented, and functional words are usually unstressed. Although functional words may be accented or stressed in certain structural types of sentences, in certain positions in a sentence they may be emphasized logically. Ex, It "is important.

2) THE DISTINCTIVE FUNCTION. Intonation distinguishes communicative types of the sen-ces, the speaker’s emotions and attitudes to the contains of the sen-ce, to the listener or to the topic of conversation.

3) Together with pitch accent SS also fulfills THE FUNCTION OF DIVIDING A SENTENCE INTO THEME AND RHEME.

Theme is the main subject of the sentence. Rheme is a part of a sentence where new information or very important information is given.

Ex. It was HE, who had stolen the bag.

Ex. It was he, who HAD STOLEN the bag (but not had returned it).