The numerous variations of English word stress are systematized in the typology of accentual structure of English words worked out by G.P. Torsuyev. He classifies them according to the number of stressed syllables, their degree or character (the main and the secondary stress). The distribution of stressed syllables within the word accentual types forms accentual structures of words. Accentual types and accentual structures are closely connected with the morphological type of words, with the number of syllables, the semantic value of the root and the prefix of the word.
The accentual types are:
1. ['___]. This accentual type marks both simple and compound words. The accentual structures of this type may include two and more syllables, e.g. 'fafher, 'possibly, 'mother-in-law, 'gas-pipe.
2. [ '_ '_ ]. The accentual type is commonly realized in compound words, most of them are with separable prefixes, e.g. 'radio-'active, 're'write, 'diso'bey.
3. [ '_' _ '_ ] and 4. ['_' _ '_ '_]. The accentual types are met in initial compound abbreviations like 'U'S'A, 'U'S'S'R.
5. ['_ ,___]. The type is realized both in simple and compound words, very
common among compound words, e.g. 'hair-,dresser, 'substructure.
6. [, _'___]. The accentual type marks a great number of simple words and some compound words as well. In simple words the stresses fall onto:
1. the prefix and the root: maga'zine;
2. the root and the suffix: ,hospi'tality;
3. the prefix and the suffix: disorganization.
The other five types are rare and found in small number of words.
The data given above suggest an idea of the great variability in the accentual structure of English words. The most widely spread among the enumerated accentual types are supposed to be Type 1, Type 2, Type 5 and Type 6. Each type includes varieties of definite accentual structures with different numbers of syllables and marks thousands of words. So the four of them cover the main bulk of most common English words and are therefore most typical for the English vocabulary.
The variability of the word accentual structure is multiplied in connected speech. The accentual structure of words may be altered under the influence of rhythm, e.g. An 'unpolished 'stone but: The 'stone was un'polished.
The tempo of speech may influence the accentual pattern of words. With the quickening of the speed the carefulness of articulation is diminished, the vowels are reduced or elided, the secondary stress may be dropped, e.g. The 'whole organi'zation of the 'meeting was 'faulty.