Focus on Word Building I. Form adjectives from these words following the pattern ir-, un-, il- + adjective makes a negative

Regular - irregularfrequented - unfrequentedaccept - acceptablefriendly - unfriendlyfinished - unfinishedfit - unfitfavourable - unfavourablenatural - unnaturallike - likableagree - agreeableunderstand - understandableeat - eatabledrink - drinkablelogical - illogicallegitimate - illegitimatereal - unrealadvise - advisableargue - arguablecommon -uncommonclear - unclearusual - unusualconscious - unconsciousnecessary - unnecessary