Which of the following is a bound morpheme used as a prefix?

• A. un-
• B. -able
• C. predict
• D. root

Answer: (A)

Bound morphemes cannot stand on their own and must attach to a base. A prefix is a bound morpheme placed at the front to change meaning. un- is a classic negation prefix; it binds to a root to give the opposite or a negated sense (for example, unhappy, unclear). Because un- cannot function as a word by itself, it fits as a bound morpheme used as a prefix. The other options don’t fit this role: -able is a bound morpheme too, but it appears at the end of a word as a suffix (readable, breakable). predict is a full word itself rather than a bound prefix, and root is a base form that can often stand alone, not a bound prefix.