4. Study Train Your Brain. Use a dictionary to find out what prefix we add to make the opposites of the underlined words in Exercise 3.

Prefixes:

• un-: attractive → unattractive; predictable → unpredictable; forgettable → unforgettable; imaginative → unimaginative; interesting → uninteresting; amazing → unamazing; awful → unawful; dull → undull; fascinating → unfascinating; terrible → unterrible.
• in-: interesting → uninteresting is the usual form; some words may use in- or its variants, such as im-, il-, or ir-.

In natural English, the most common opposites in this list are: unattractive, unpredictable, unforgettable, unimaginative, uninteresting. The other adjectives do not usually form common opposites simply by adding a prefix; antonyms such as good, exciting, memorable or pleasant are normally used.