Many words are easy to misspell because of the way in which their stress pattern affects their pronunciation. When they occur in unstressed syllables, the different vowel sounds merge into a sound like uh or er. You may then find it difficult to remember which vowel is correct in a particular word.
• People often confuse unstressed e and a in words like category, desperate, separate, grammar. It is easy to muddle pairs such as allude and elude, affect and effect, which have very similar pronunciations.
• You may want to write unstressed e as er, especially in words like integrate which it is easy to confuse with words beginning with inter-.
• It's easy to confuse o with both a and e in unstressed syllables. Words which you may find difficult include corroborate (not -erate) and propaganda (not propo-).
• In unstressed syllables e sometimes has a short i sound. You may find it hard to remember which words spell this sound with an e (e.g. artefact, benefit, indigenous, liquefy) and which spell it with an i (e.g. dilapidated, purify). It is easy to confuse elicit with illicit.