Word formation: prefixes
Negative prefixes (un-, in-, im-, ir-, il-, dis-, mis-), re-, over-, under-, and positive in- words like invaluable.
Negative prefixes are one of the biggest traps in C1 Part 3. The meaning of the whole text tells you when you need one – and the base word tells you which one.
Negative prefixes
Other prefixes
How it comes up in Part 3
In Part 3 you change the word in capitals so that it fits the gap: the right kind of word, the right form and the right spelling.
PRECEDENT
Nothing like it had happened before: un- + precedent + -ed.
REPLACE
ir- + replace + -able.
VALUE
Invaluable means extremely useful – not the opposite of valuable!
Common mistakes
- ✗ The results were inreliable.✓ The results were unreliable.Reliable takes un-.
- ✗ His arguments were unlogical.✓ His arguments were illogical.il- before l.
- ✗ Her help was unvaluable.✓ Her help was invaluable.Invaluable = very valuable.
If the text suggests something bad, missing or opposite, try a negative prefix – but check that the whole word exists. Say it in your head: 'unlogical' sounds wrong, 'illogical' sounds right.
Quick check
Use the word in capitals to form a word that fits the gap.
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