What Is a Schwa Sound?

Schwa is a particular like a phoneme in English pronunciation and it's probably the most common. A schwa is basically a vowel sound which is like a sort of dead sound, so usually in the stressed syllable of a word, the vowel sound is pronounced fully. Now in the unstressed syllable the vowel sound has been made weaker to make an 'ah' sound - just like when you say shut up.