Educational worksheet on using "Could" and "Should" in English grammar with interactive exercises and illustrations.

Let's solve the worksheet step by step, based on the grammar rules provided:

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Part 1: Could, Couldn't

Rule: *We use "Could" to talk about ability in the past or polite requests.*

#### Fill in the blanks with could or couldn't:

1. I couldn't swim last year, I was afraid of water.
→ Past inability (fear of water).

2. Could you, please, open the door?
→ Polite request.

3. Sam could win the medal, but he fell down.
→ He had the ability to win, but didn't due to falling.

4. They couldn't play Soccer, the weather was rainy.
→ They were unable to play because of rain.

5. Dana could arrive in time, but she missed the train.
→ She had the possibility/ability to arrive on time, but failed.

6. John couldn't play Tennis, but now he plays good.
→ Past inability, now able.

7. He couldn't type his essay, his computer had broken.
→ Unable to type due to broken computer.

8. He couldn't talk at all last week, he had no voice.
→ Inability to speak due to illness.

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Part 2: Should, Shouldn't

Rule: *We use "Should" to express advisability, obligation, or probability.*

#### Fill in the blanks with should or shouldn't:

1. She should study harder to pass the exam.
→ Advice for success.

2. You should take more care of yourself. You are looking very tired.
→ Recommendation for health.

3. I should pay attention in class.
→ Obligation or responsibility.

4. We shouldn't eat fast food! It's bad for our health.
→ Advice against something harmful.

5. You should help your friends when they need it.
→ Moral advice / kindness.

6. You should stay home. You're sick!
→ Advice for health and safety.

7. Students shouldn't gossip during the lesson.
→ Rule / behavior not allowed in class.

8. You shouldn't talk back to your parents.
→ Social rule / proper behavior.

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✔ Final Answers:

#### Could / Couldn't:
1. couldn't
2. Could
3. could
4. couldn't
5. could
6. couldn't
7. couldn't
8. couldn't

#### Should / Shouldn't:
1. should
2. should
3. should
4. shouldn't
5. should
6. should
7. shouldn't
8. shouldn't

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📝 Explanation Summary:

- Could / Couldn't: Used for past abilities or polite requests.
- Example: "I couldn't swim" = past inability.
- Example: "Could you open the door?" = polite way to ask.

- Should / Shouldn't: Used to give advice, recommendations, or rules.
- Example: "You should rest" = good advice.
- Example: "You shouldn't shout" = rule or warning.

This worksheet helps students practice using modal verbs correctly in context — focusing on past ability and giving advice.