Word Building for PET Negative Prefixes 1 Negative Prefixes 2 Prefixes (UN, DIS, IM, IN, MIS, IR) 1 Prefixes (UN, DIS, IM, IN, MIS, IR) 2 Prefixes (UN, DIS, IM, IN, IL, IR) 3 Suffixes (OR, ER, IST) Suffixes (MENT, ITY, NESS, TION) Suffixes (Y, ED, FUL, (I)OUS) Suffixes (ABLE, LESS, IVE, AL) Prefix Meanings