What you need to know
To achieve 100 you need to correctly spell words with prefixes.
- Most prefixes are added at the beginning of root words without any changes in spelling. So, if a word begins with the same letter as the end of the prefix, both letters are used (e.g. dis + satisfy = dissatisfy, un + necessary = unnecessary).
- Some prefixes have negative meanings (e.g. dis + appoint, mis + behave, un + do).
- Do not confuse dis and des:
When a word begins with dis, you can usually remove dis and a root word will still exist (e.g. disappear = dis + appear).
When a word begins with des, it doesn't usually make sense if you remove the des (e.g. despise, describe).
- The prefix in means not when used before words beginning with most letters, except:
before a root word starting with l (in becomes il);
before a root word starting with m or p (in becomes im);
before a root word starting with r (in becomes ir).
- Prefixes can be used for a range of meanings: re = again or back; sub = under; inter = between; super = above; anti = against; auto = self.