With Answer Keys! - Free Printable

Let's solve each sentence by adding the correct prefix or suffix to the word in brackets, using the provided lists of prefixes and suffixes. We’ll also explain how we chose each answer.

---

Prefixes: DIS-, UN-, IM-, RE-

Suffixes: -ING, -ED, -ANCE, -FUL, -ABLE, -LY, -OUS, -ER

---

1. I can't answer this question. It's ............... (POSSIBLE).
→ Use IM- (prefix meaning "not") + POSSIBLE = IMPOSSIBLE
✔ Answer: impossible

2. Don't stand near the water. It's too ............... (DANGER).
→ Add -OUS (suffix for adjectives) to DANGER → DANGEROUS
✔ Answer: dangerous

3. I don't like this fish. It's not very well ............... (COOK).
→ Add -ED (past participle form) → COOKED
✔ Answer: cooked

4. Kate started crying because she was so ............... (HAPPY)
→ Use UN- (opposite) → UNHAPPY
✔ Answer: unhappy

5. If you have a haircut it will change your ............... (APPEAR)
→ Add -ANCE (to make a noun from a verb) → APPEARANCE
✔ Answer: appearance

6. Paul never waits in queues. He is too ............... (PATIENT)
→ Use IM- (impatient = not patient) → IMPATIENT
✔ Answer: impatient

7. Thank you for your advice. You have been very ............... (HELP)
→ Add -FUL (meaning "full of") → HELPFUL
✔ Answer: helpful

8. Stealing other people's money is ............... (HONEST)
→ Use DIS- (opposite) → DISHONEST
✔ Answer: dishonest

9. Our science ............... is very young. (TEACH)
→ Add -ER (to make a person who does something) → TEACHER
✔ Answer: teacher

10. Harry didn't think the book was very ............... (INTEREST).
→ Add -ING → INTERESTING (adjective describing the book)
✔ Answer: interesting

11. A million pounds was given to the hospital by an ............... person (KNOWN)
→ Use UN- → UNKNOWN
✔ Answer: unknown

12. When you ............... this paragraph, make it a bit shorter (WRITE)
→ Use RE- (again) → REWRITE
✔ Answer: rewrite

13. Mary was wearing a/an ............... hat (USUAL)
→ Use UN- → UNUSUAL
✔ Answer: unusual

14. That was a great film. It was really ............... (ENJOY)
→ Add -ABLE → ENJOYABLE
✔ Answer: enjoyable

15. I like this town. The people are very ............... (FRIEND)
→ Add -LY → FRIENDLY
✔ Answer: friendly

16. I don't think you're right. I ............... with you completely (AGREE)
→ Use DIS- → DISAGREE
✔ Answer: disagree

---

✔ Final Answers:

1. impossible
2. dangerous
3. cooked
4. unhappy
5. appearance
6. impatient
7. helpful
8. dishonest
9. teacher
10. interesting
11. unknown
12. rewrite
13. unusual
14. enjoyable
15. friendly
16. disagree

---

🔍 Explanation Summary:

- Prefixes change the meaning (e.g., *un-* = not, *im-* = not, *dis-* = opposite, *re-* = again).
- Suffixes change the part of speech (e.g., *-ful* = full of, *-able* = capable of, *-er* = person who does, *-ing* = present participle).
- Always consider grammar and context when choosing the correct affix.

Let me know if you'd like this as a printable worksheet!