Vocabulary and Word Formation
What the section tests
You must show you can choose the right word for a context, form new words with prefixes and suffixes, and understand relationships such as synonyms, antonyms, and collocations.
Concepts to master
- Prefixes change meaning: un-, in-, im-, dis-, mis-, re-, pre-, over-, under- (e.g., unfair, impossible, rewrite, misunderstand).
- Suffixes change word class: nouns (-tion, -ment, -ness, -ity), adjectives (-ful, -less, -ous, -ive, -able), adverbs (-ly), verbs (-ise/-ize, -en).
- Collocations: words that naturally go together - make a decision, take a break, heavy rain, strong wind.
- Synonyms and antonyms: choose the closest meaning or the opposite.
- Context clues: the surrounding sentence often tells you the word class and meaning needed.
Traps to watch for
- Choosing a real word of the wrong class: success (noun) vs. successful (adjective) vs. successfully (adverb).
- Spelling changes on suffixation: happy → happiness (y→i), big → bigger (double consonant), decide → decision.
- False friends from Portuguese: actually means in fact, not currently; pretend means fazer de conta.
- Similar-sounding words: affect (verb) vs. effect (noun).
Rule of thumb
Read the gap and decide what word class is needed (noun, verb, adjective, adverb) from the words around it - then apply the correct prefix or suffix.
Worked example: "Her ______ (kind) surprised everyone." The possessive her needs a noun, so kind → kindness (not kindly or kindful).