Phoneticians divide syllables into strong (heavy) and weak (light).
A strong syllable contains a long vowel or a diphthong or a short vowel plus two consonants; syllables with a short vowel and no coda are weak ones. Only strong syllables can be stressed (although not all of them), but weak syllables are never stressed. Factors that may determine the placement of stress are: the morphological structure of the word (whether it is simple, complex or compound), its grammatical category (noun, verb, adjective, etc.
The word stress in English as well as in Russian is not only free, but it may also be shifting, thus differentiating lexical units, parts of speech and grammatical forms: ? contrast – con? trast, ? transport – trans? port, ? замок – за? мок, ? мука – му? ка) and the number of syllables in the word. Besides the stress pattern of English words can vary under the influence of some factors. First of all in the present day English stress can shift under the influence of rhythm to avoid a succession of weak syllables (stress shifts to the second syllable, or the third one from the end.
In compounds the stress on a final-stressed compound tends to move to a preceding syllable if the following word begins with a strongly stressed syllable. The stress pattern can change under the influence of tempo as well; in this case secondary stresses are dropped. It sometimes happens that a word’s stress pattern is influenced not only by rhythm, but also by the stress structure of a derivative. Some linguists also distinguish tertiary stress, which is as weak as secondary but has a different distribution: it follows the primary stress, while the secondary stress precedes it. Tertiary stress is usually found in American English.
Speech sounds are vibrations that travel through a medium (usually air) by displacing the molecules of this medium. Depending on the consistency of the given medium, the sounds travel at different speeds and have varying intensities. This is why we sound differently when we speak under normal circumstances from when we try to talk under water and also why it is completely impossible for speech ...
Word stress can be fixed (or limited to a particular syllable – the last in French, the last but one in Polish, the first in Czech) or free (or variable).
English word-stress has many peculiarities, which make it very complicated. These peculiarities are due to the fact, that in English there are many borrowed words from different languages with various rules of syllable formation. Though stress placement in English words is free it follows certain rules.