Prefix and suffix exercise worksheet for English language learners.

Here’s the completed exercise with explanations for each answer. We are to use a prefix (DIS-, UN-, IM-, RE-) or a suffix (-ING, -ED, -ANCE, -FUL, -ABLE, -LY, -OUS, -ER) to form a new word from the base word in brackets and complete the sentence logically.

---

✔ Answers & Explanations:

1. I can't answer this question. It's __________. (POSSIBLE)
→ impossible
*Explanation:* “Possible” becomes “impossible” by adding the prefix IM-, which means “not.” The context says the speaker can’t answer — so it’s *not possible*.

---

2. Don't stand near the water. It's too __________. (DANGER)
→ dangerous
*Explanation:* Add suffix -OUS to “danger” → “dangerous” (meaning full of danger). Fits the warning tone.

---

3. I don't like this fish. It's not very well __________. (COOK)
→ cooked
*Explanation:* Add suffix -ED to “cook” → “cooked” (past participle). Describes how the fish was prepared.

---

4. Kate started crying because she was so __________. (HAPPY)
→ unhappy
*Explanation:* Add prefix UN- to “happy” → “unhappy” (not happy). Crying suggests sadness, so she was *not happy*.

---

5. If you have a haircut it will change your __________. (APPEAR)
→ appearance
*Explanation:* Add suffix -ANCE to “appear” → “appearance” (the way someone looks). A haircut changes how you look.

---

6. Paul never waits in queues. He is too __________. (PATIENT)
→ impatient
*Explanation:* Add prefix IM- to “patient” → “impatient” (not patient). Not waiting in queues = lacks patience.

---

7. Thank you for your advice. You have been very __________. (HELP)
→ helpful
*Explanation:* Add suffix -FUL to “help” → “helpful” (full of help). Giving good advice = being helpful.

---

8. Stealing other people's money is __________. (HONEST)
→ dishonest
*Explanation:* Add prefix DIS- to “honest” → “dishonest” (not honest). Stealing is the opposite of honesty.

---

9. Our science __________ is very young. (TEACH)
→ teacher
*Explanation:* Add suffix -ER to “teach” → “teacher” (one who teaches). Refers to the person teaching science.

---

10. Harry didn't think the book was very __________. (INTEREST)
→ interesting
*Explanation:* Add suffix -ING to “interest” → “interesting” (causing interest). The book didn’t cause interest → not interesting.

---

11. A million pounds was given to the hospital by an __________ person. (KNOWN)
→ unknown
*Explanation:* Add prefix UN- to “known” → “unknown” (not known). The donor’s identity wasn’t revealed.

---

12. When you __________ this paragraph, make it a bit shorter. (WRITE)
→ rewrite
*Explanation:* Add prefix RE- to “write” → “rewrite” (write again). The instruction is to write it again, but shorter.

---

13. Mary was wearing a/an __________ hat. (USUAL)
→ unusual
*Explanation:* Add prefix UN- to “usual” → “unusual” (not usual). Suggests the hat was strange or out of the ordinary.

---

14. That was a great film. It was really __________. (ENJOY)
→ enjoyable
*Explanation:* Add suffix -ABLE to “enjoy” → “enjoyable” (capable of being enjoyed). A great film = enjoyable.

---

15. I like this town. The people are very __________. (FRIEND)
→ friendly
*Explanation:* Add suffix -LY to “friend” → “friendly” (having the qualities of a friend). People are kind and welcoming.

---

16. I don't think you're right. I __________ with you completely. (AGREE)
→ disagree
*Explanation:* Add prefix DIS- to “agree” → “disagree” (not agree). Since the speaker thinks the other is wrong, they *don’t agree*.

---

📝 Final Answer List:

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

✔ All answers use one prefix or suffix from the given lists and fit the context of the sentences.