An unstressed vowel
is the vowel
sound that forms the syllable peak
of a syllable
that has no lexical stress
. In many languages, such as Russian
, vowel reduction
happens when a vowel changes from stressed to unstressed position, i.e., an unstressed vowel becomes a reduced vowel
, such as schwa
. As a result, the pronunciation of , e.g., a letter E
may significantly differ in the same syllable, but in stressed and unstressed positions. Some other languages, such as Finnish
, have no unstressed vowel reduction.
In some dictionary transcriptions of American English, only a subset of vowels may occur in unstressed syllables. Other vowels, such as and , are always transcribed with at least secondary stress. However, when dictionary-convention secondary stress is distinguished from absence of vowel reduction
(see the article on secondary stress
), it is apparent that all English vowels may occur in unstressed positions:
Nonetheless, it is true that some vowels, such as and , reduce quite readily, so that there are not many English words which have them in unstressed positions.