Download Programme 1 from the archived page on pronunciation tips on the BBC Learning English website,
Schwa is the most common sound in the English language. It occurs only in unstressed syllables and getting it correct helps spoken English to sound more natural and fluent. Any vowel letter can be pronounced as schwa and the pronunciation of a vowel letter can change depending on whether the syllable in which it occurs is stressed or not.
See below for some tongue twisters for speakers of different languages, to help you to practise difficult pronunciation.