Vocabulary and Word Usage: Building and Choosing Words
Vocabulary questions are quick marks, but they are marked strictly: a near-miss synonym, a wrong prefix spelling or a misread idiom scores zero.
Word-building
- Prefixes change meaning: un-, dis-, mis-, non-, re-, pre-, over-, under-.
- The negative in- assimilates to the next letter: impossible, immobile (before p, b, m); illegal, illiterate (before l); irregular, irresponsible (before r); invisible, inactive elsewhere.
- Suffixes change word class: -ness, -ment, -tion, -ance make nouns; -able, -ful, -less, -ive make adjectives; -ly makes adverbs; -ist, -er make personal nouns.
- Compounds: two free words joined - bookshop, blackboard.
- Blends: parts of two words fuse - smog (smoke + fog), brunch, motel, netizen.
- Clipped words: ad, exam, gym, fridge, photo.
- Phrasal verbs carry a new meaning: put off = postpone, call off = cancel, give in = surrender.
Worked example. "Use the correct form of just to complete: The punishment was clearly ___." The slot needs an adjective meaning "not fair" → unjust, not injust (that form does not exist). Compare unbelievable and impossible: the prefix is fixed by usage, so learn the common families rather than applying one rule everywhere.
Traps
- Reading an idiom literally (once in a blue moon = rarely).
- Choosing a synonym with the right meaning but the wrong part of speech.
- Writing inlegal or inregular instead of illegal, irregular.
- Ignoring collocation: make a mistake, never do a mistake.