Prefix and suffix worksheet for students to practice completing words with correct prefixes.

Let's solve this Prefix and Suffix worksheet step by step. The goal is to choose the correct prefix (a word part added to the beginning of a root word) to complete each sentence logically and grammatically.

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🔍 Understanding Prefixes:

Common prefixes include:
- pre- = before
- re- = again, back
- dis- = not, opposite
- mis- = wrong
- over- = too much
- under- = less than
- un- = not
- pro- = forward, in favor of
- post- = after
- re- = again

We’ll analyze each sentence and pick the best prefix that makes sense.

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✔ Answers with Explanations:

1. Mom had to _____heat the oven to 350° to bake the cake.
→ Preheat means to heat something *before* using it.
✔ Answer: pre

2. To help keep the Earth clean, we cycle all of our plastic.
→ "Cycle" here is a verb meaning to recycle. But the word should be recycle – to reuse materials.
✔ Answer: re

3. I looked over my writing and found a _____spelled word.
→ A word that is spelled incorrectly = misspelled.
✔ Answer: mis

4. Before you take off your shoes, you need to _____tie them.
→ You tie your shoes *before* taking them off? No — actually, you untie them first. So the correct word is untie.
✔ Answer: un

5. You may be correct, but I _____agree with you.
→ This suggests disagreement. So “I disagree” makes sense.
✔ Answer: dis

6. We checked the _____cast before we planned the event.
→ We check the forecast (predicting weather) before planning.
✔ Answer: fore

7. The big, gray _____marine plunged down into the water.
→ This is likely referring to a whale, which is a mammal. But the word is "marine mammal" — so the missing prefix is "mam"? Wait — no. Let’s look at the structure:
The blank is before "marine", but the word is likely "mammal", so maybe the sentence meant:
*"The big, gray ______ marine animal..."* — but the word is "mammal", and it's already given as "marine". Hmm... Actually, perhaps it's a typo or misprint?

Wait — let’s re-read:
> "The big, gray _____ marine plunged down..."

That doesn't make sense. But if it's "The big, gray whale", then it might be a typo. Alternatively, could it be "The big, gray (sub)marine?" — but that doesn’t fit "plunged down".

Another possibility: "The big, gray mammal marine" — still awkward.

Wait — perhaps it's "The big, gray marine mammal" — but the blank is before "marine"? That seems off.

Let’s reconsider: Maybe the intended word is "mammal", and the blank is for "mam"? But that’s not a prefix.

Alternatively, perhaps the word is "marine" with a prefix? But "marine" doesn't typically take prefixes like this.

Wait — another idea: Could it be "The big, gray submarine"? Yes! A submarine is a vessel that goes under water.

So: "The big, gray submarine plunged down into the water."
→ "Sub" is a prefix meaning under or below.

✔ Answer: sub

8. If you want to be ready for something, you need to _____pare.
→ "Prepare" = get ready. The prefix is pre- (before).
✔ Answer: pre

9. Make sure you _____turn the library book on time!
→ Return = give back. "Return" = re- + turn.
✔ Answer: re

10. I try to be careful but sometimes I make a _____take.
→ "Mistake" = an error. The prefix is mis- (wrong).
✔ Answer: mis

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✔ Final Answers:

| # | Word | Correct Prefix |
|---|------|----------------|
| 1 | preheat | pre |
| 2 | recycle | re |
| 3 | misspelled | mis |
| 4 | untie | un |
| 5 | disagree | dis |
| 6 | forecast | fore |
| 7 | submarine | sub |
| 8 | prepare | pre |
| 9 | return | re |
|10 | mistake | mis |

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📝 Summary of Completed Sentences:

1. Mom had to preheat the oven to 350° to bake the cake.
2. To help keep the Earth clean, we recycle all of our plastic.
3. I looked over my writing and found a misspelled word.
4. Before you take off your shoes, you need to untie them.
5. You may be correct, but I disagree with you.
6. We checked the forecast before we planned the event.
7. The big, gray submarine plunged down into the water.
8. If you want to be ready for something, you need to prepare.
9. Make sure you return the library book on time!
10. I try to be careful but sometimes I make a mistake.

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✔ All sentences now make logical and grammatical sense with the correct prefixes.

Let me know if you'd like a printable version or explanation for younger learners!