In linguistics, specifically phonetics and phonology, schwa (sometimes spelled shwa) refers to the mid-central vowel sound (rounded or unrounded) in the middle of the vowel chart, denoted by the IPA symbol ə, or another vowel sound close to that position. An example in English is the vowel sound in the 'a' of the word 'about'. Schwa in English is mainly found in unstressed positions, but in some other languages it occurs more frequently as a stressed vowel.
In relation to certain languages, the name "schwa" and the symbol ə may be used for some other unstressed and toneless neutral vowel, not necessarily mid-central.
Etymology
The word schwa is from the Hebrew word shva (שְׁוָא IPA: [ʃva], classical pronunciation: shewa’ [ʃəˈwa]), designating the Hebrew niqqud vowel sign shva (two vertical dots written beneath a letter), which in Modern Hebrew indicates either the phoneme /e/ or the complete absence of a vowel. (The Hebrew shva is also sometimes transliterated using the schwa symbol ə, even though the schwa vowel is not representative either of the modern Hebrew pronunciation of shva or of earlier pronunciations; see Tiberian vocalization → Mobile Shwa.) The term was introduced into European linguistics by Jacob Grimm in the early 19th century,[citation needed] so the spelling sch is German in origin. It was first used in English texts between 1890 and 1895.
The symbol ⟨ə⟩ was first used by Schmeller for the reduced vowel at the end of German gabe. Ellis, in his palæotype alphabet, used it for the similar English sound in but.
Description
Main articles: Epenthesis, Unstressed vowel and Vowel reduction
Sometimes the term "schwa" is used for any epenthetic vowel, even though different languages use different epenthetic vowels (e.g. the Navajo epenthetic vowel is [i]).
In English, schwa is the most common vowel sound. It is a reduced vowel in many unstressed syllables, especially if syllabic consonants are not used. Depending on dialect, it may correspond to