There are a lot of words in English that look or sound alike but have very different meanings. It’s easy to get them confused and most electronic spellcheckers won’t be much help in this type of situation: they can tell you if a word has been spelled wrongly but they can’t generally flag up the misuse of a correctly spelled word.

Here are some pairs of words that regularly cause people problems:

adverse:  unfavourable, harmful
averse:     strongly disliking; opposed

appraise: to assess
apprise:     to inform someone

assent:     agreement, approval
ascent:     the action of rising or climbing up

 Source: en.oxforddictionaries.com