IRRegular-irregularRelevant-irrelevantRational-irrationalResponsible-irresponsible

UNHappy-unhappyTrue-untrueComfortable-uncomfortable

Necessary-unnecessaryFriendly-unfriendly

INCorrect-incorrect

Decisive-indecisive Appropriate-inappropiate

Curable-incurable Finite-infinite

ILLegal-illegal

Logical-illogicalLiterate-illiterateLegible-illegible

IMPosible-imposible Mature-immature Proper-improper Mortal-immortal Mobile-immobile