Introduction to Schwa /ə/
The reduced vowel sound called schwa is the most common vowel sound in spoken English. Schwa is a quick, relaxed, neutral vowel pronunciation very close to a short u. The purpose of schwa is to allow unstressed syllables to be said more quickly so the main beats of spoken words are easier to place on the stressed syllables.
Schwa does not have an exact and standard pronunciation. Due to the near-identical pronunciation of schwa and short u, many dictionaries merge the transcription of the two sounds and strictly use /ə/. Separate symbols are retained here to indicate whether a vowel sound falls on a stressed or unstressed syllable.
Schwa occurs in two different circumstances:
- in an unstressed syllable of a multi-syllable word
- as a reduced vowel sound in a function word
Schwa in an unstressed syllable
In words with more than one syllable, not every syllable is given equal emphasis when spoken. Three levels of syllable stress are possible:
- secondarily stressed
Every multi-syllable word has a single stressed syllable. The single stressed syllable of the word has the most emphasis. The remainder of the syllables may have a secondary stress or may be unstressed.
The word emphasize has all the levels of stress. The first syllable is stressed, the second syllable is an unstressed syllable pronounced as schwa, and the third syllable has a secondary stress.
The spelling of schwa
Many multi-syllable words do not seem to be pronounced as they are spelled. This is because schwa is a function of syllable stress and not of spelling. Once learners can recognize stressed syllables, it becomes easier to predict when schwa will be used in an adjacent, unstressed vowel, regardless of the spelling. The examples below show schwa as it is exhibited when spelled with each vowel. The unstressed vowel sound, schwa, is underlined in each word.
Dictionaries and schwa
Even for stressed syllables, some dictionaries do not use a separate symbol for schwa /ə/ and the short u /ʌ/. When schwa is the only symbol used, it can be assumed that the word is pronounced with the short u sound. The table below compares the transcription used by Merriam-Webster OnLine Dictionary and Cambridge Dictionary of American English.
Introduction to schwa in function words
Proper use of schwa helps speakers adopt and maintain English sentence stress patterns. Certain grammatical words called function words can have two different pronunciations in spoken English: a citation form and a reduced form.
The citation form of a word is the pronunciation shown first in a dictionary transcription. It is the pronunciation used when the word is spoken alone or out of context. Citation form pronunciation is actually less common than the reduced pronunciation of function words.
If a dictionary transcribes reduced forms of words, it is usually noted as a secondary transcription. If this transcription shows the vowel sound of function words reduced to schwa, the vowel sound of the word is said quicker and with a more neutral vowel sound than the citation pronunciation. Function words are typically only reduced when the word is used within a sentence, and not if the word is being spoken in isolation. The purpose of reduced pronunciations is to help function words fall into the background of speech, while content words gain emphasis.