Grade 3 Grammar Topic 40: Modal Auxiliary Words Worksheets - Lets ... - Free Printable

Let's solve each sentence by choosing the correct modal auxiliary verb from the list provided. Remember, modal verbs express necessity, possibility, permission, obligation, or ability.

Here’s the list of modals for reference:

| Modal | Negative | Contraction |
|-------|----------|-------------|
| shall | shall not | won't |
| will | will not | won't |
| may | may not | mayn't |
| might | might not | mightn't |
| can | can not | can't |
| could | could not | couldn't |
| must | must not | mustn't |
| should | should not | shouldn't |
| would | would not | wouldn't |
| ought to | ought not to | — |

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1. She ____________ believe she got a 90% on her history test.

- This expresses surprise or disbelief.
- "She can't believe..." means it's unbelievable that she got such a high score.
- Correct answer: can't

✔ She can't believe she got a 90% on her history test.

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2. Jane ____________ join us for our study group tonight.

- We are expressing invitation or possibility.
- "Jane might join us" suggests possibility – we're not sure.
- "Jane could join us" also works, but "might" is more natural here for uncertain future plans.
- However, "may" is also acceptable (slightly more formal).
- But in modern English, "might" is often preferred for uncertainty.

✔ Jane might join us for our study group tonight.

*(Alternatively: "Jane may join..." – both are correct, but "might" is slightly better for uncertainty.)*

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3. Mike ____________ go skiing with us, but he has to work.

- The second part says "but he has to work", which implies he wants to go but cannot.
- So we need a modal expressing desire or willingness that is blocked.
- "Mike would go skiing with us..." indicates willingness if possible.
- "Would" fits perfectly here.

✔ Mike would go skiing with us, but he has to work.

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4. Rob refuses to go with us because he ____________ leave his little brother home alone.

- Rob is refusing because of a moral or emotional obligation.
- He must not leave his brother alone – it's not allowed.
- So we use must not = prohibition.

✔ Rob refuses to go with us because he must not leave his little brother home alone.

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5. I ____________ imagine having to start school at 6 am!

- This expresses strong disbelief or impossibility.
- "I can't imagine..." means it's too hard to picture.
- "Can't" shows inability to mentally process such an idea.

✔ I can't imagine having to start school at 6 am!

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6. You ____________ forget to turn in your homework.

- This is about warning or advice.
- We want to say: "You should not forget..."
- Or more commonly: "Don't forget..." → but we must choose a modal.
- The best fit is shouldn't (should not) – giving advice.

✔ You shouldn't forget to turn in your homework.

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✔ Final Answers:

1. can't
2. might (or may)
3. would
4. must not
5. can't
6. shouldn't

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Summary of Answers:

1. She can't believe she got a 90% on her history test.
2. Jane might join us for our study group tonight.
3. Mike would go skiing with us, but he has to work.
4. Rob refuses to go with us because he must not leave his little brother home alone.
5. I can't imagine having to start school at 6 am!
6. You shouldn't forget to turn in your homework.

Let me know if you'd like explanations in simpler terms or want to practice more!