In English, we do not say each syllable with the same force or strength. We say one syllable very loudly (big, strong, important) and all the other syllables very quietly. stress is the relative emphasis that may be given to certain syllables in a word, or to certain words in a phrase or sentence. The term is also used for similar patterns of phonetic prominence inside syllables. The word accent is sometimes also used with this sense.
'Primary' and 'secondary' stress are distinguished in some languages. English is commonly believed to have two levels of stress, as in the words cóunterfòil [ˈkaʊntərˌfɔɪl] and còunterintélligence [ˌkaʊntər.ɪnˈtɛlɪdʒəns], and in some treatments has even been described as having four levels, primary, secondary, tertiary, and quaternary, but these treatments often disagree with each other. There are two very important rules about word stress:
One word, one stress. (One word cannot have two stresses. So if you hear two stresses, you have heard two words, not one word.)
The stress is always on a vowel.
