FCE Use of English Part 3 always tests word formation. You are given a base word and must change it to fit the gap. Most gaps require nouns, adjectives, verbs or adverbs.
-tion / -sion
innovate → innovation · discriminate → discrimination
-ment
achieve → achievement · employ → employment
-ness
aware → awareness · weak → weakness
-ity
diverse → diversity · equal → equality
-ance / -ence
resist → resistance · depend → dependence
-er / -or / -ist
employ → employer · innovate → innovator