7. The structure & functions of utterance-stress. Peculiarities of English utterance-stress.

Utterance-stress (sentence-stress) is a prosodic phenomenon of speech with a linguistic function of indicating the relative importance of various elements in an utterance. This function is manifested through phonetic contrastivity of successive syllables in an utterance perceived as their different phonetic prominence.

The effect of phonetic prominence is based on a complex of prosodic modifications which can be in a general way described as an increase of the force of articulation (intensity), length (duration) and pitch level (fundamental frequency of the voice).

The identification of utterance stress depends on pitch modifications more than on any other prosodic parameter. A word carrying utterance stress is at the same time the carrier of a tone which is defined as a combination of a pitch change (or pitch contrast) with the force of articulation, and the number of stresses in an utterance coincides with the number of tones.

Although utterance-stress is realised through syllabic prominence, it actually embraces the whole word. That is, when we deal with utterance-stress we speak about the prominence of words carrying greater semantic weight for the message being conveyed. Consequently, it would be more accurate to define peculiarities of English utterance-stress in terms of contrasts between prominent and non-prominent words.

The occurrence and the distribution of utterance-stress in an English utterance are determined by factors of two kinds: semantic and rhythmic.

The influence of the rhythmic factor manifests itself mainly in the placement of prenuclear stresses, the number and the distribution of which depend not only on the semantic weight of the words in this part of the intonation-group but also on the ten­dency towards alternating prominent and non-prominent elements in the speech flow.

The assumption that utterance-stress in English (as in Russian, Belarusian and many other languages) is predicted semantically means that its placement in a given sentence is determined by the circumstances of the speech situation and speech context.

The classification of English words according to their accentability as in most other languages is based on the following general principle: stress on notional words and absence of stress on function words.

Another difficulty is that monosyllabic function words, when unstressed, have in many cases a weakened vowel in English. In other words, the use of a vowel of full quality (or quantity), i.e. the use of a strong form, in this position leads to a considerable foreign accent and can even hamper correct understanding. The list of function words includes articles, particles, prepositions, conjunctions, some pronouns, auxiliary and modal verbs.

According to their pronunciation in an unstressed position function words can be divided into several groups. The first group consist of words that are never used in their strong form in an unstressed position in an utterance. The second group includes auxiliary and modal verbs as well as prepositions which are reduced when unstressed at the beginning or in the middle of an utterance, but retain their strong form when unstressed at the end of an utterance (or for some of the function words at the beginning of it). The third group is for words that retain their strong form regardless of stress or utterance position