Last updated on October 16th, 2026 at 12:17 pm
I could swim when I was six. Could you help me, please? We could take a taxi. All three sentences use could, but each one has a different meaning. The first is about the past, the second is polite, and the third is a suggestion.
Could is a modal verb. It is one of the most useful words in English, because it helps us speak about ability, possibility and polite requests.
This lesson explains the uses of could in simple words. It gives 50 sentences with could, then exercises, a quiz and a FAQ.
- The structure of could, with negative and question forms
- Six common uses of could
- 50 sentences with could in five groups
- The difference between can and could
- How to avoid common mistakes, with exercises and a quiz
Structure of Could
Quick Navigation
Could has one form for every subject. It never takes -s, and the verb after it stays in the base form.
| Form | Structure | Example |
|---|---|---|
| Positive | Subject + could + base verb | He could swim. |
| Negative | Subject + could not (couldn’t) + base verb | He couldn’t swim. |
| Question | Could + subject + base verb? | Could he swim? |
| Short answer | Yes, he could. / No, he couldn’t. | Yes, he could. |
Do not say could to swim or could swam. After could, use the base verb only.
Uses of Could
Could has six common uses. The table shows each one with an example.
| Use | Example |
|---|---|
| Ability in the past | I could run fast when I was young. |
| A polite request | Could you open the door, please? |
| Permission (a polite question) | Could I use your pen? |
| Possibility now or later | It could rain this evening. |
| A suggestion | We could eat at home tonight. |
| A past chance that did not happen | She could have won the race. |
Check your answer
Could and Was Able To
We use could for general ability in the past. For one single event, we use was able to or managed to.
- General: I could swim when I was six.
- One event: I was able to finish the test yesterday.
In negative sentences, couldn’t works for both. We can say I couldn’t finish the test yesterday.
50 Sentences with Could
The sentences are in five groups. Each group shows one use or form.
Ability in the Past
| No. | Sentence |
|---|---|
| 1 | I could swim when I was six. |
| 2 | My grandfather could fix any radio. |
| 3 | She could sing very well as a child. |
| 4 | We could run for hours when we were young. |
| 5 | He could speak three languages at school. |
| 6 | The old man could hear every small sound. |
| 7 | My sister could draw faces at the age of ten. |
| 8 | Our dog could jump over the fence. |
| 9 | They could read before they started school. |
| 10 | I could see the sea from my old window. |
Polite Requests and Permission
| No. | Sentence |
|---|---|
| 11 | Could you help me, please? |
| 12 | Could you close the window? |
| 13 | Could you speak more slowly? |
| 14 | Could you lend me a pen? |
| 15 | Could I borrow your book? |
| 16 | Could I sit here? |
| 17 | Could we start now? |
| 18 | Could you send me the file by email? |
| 19 | Could I ask you a question? |
| 20 | Could you show me the way to the station? |
Possibility and Suggestions
| No. | Sentence |
|---|---|
| 21 | It could rain this evening. |
| 22 | The shop could be closed today. |
| 23 | That could be the answer. |
| 24 | He could be at the library now. |
| 25 | We could eat at home tonight. |
| 26 | You could ask your teacher for help. |
| 27 | We could take a taxi to the airport. |
| 28 | They could visit us on Sunday. |
| 29 | You could try a different bus. |
| 30 | We could watch a film after dinner. |
Could Have: Past Chances
| No. | Sentence |
|---|---|
| 31 | She could have won the race. |
| 32 | I could have called you, but I forgot. |
| 33 | We could have caught the train. |
| 34 | He could have been a doctor. |
| 35 | You could have told me the truth. |
| 36 | They could have stayed longer. |
| 37 | The cat could have fallen from the roof. |
| 38 | I could have studied harder for the test. |
| 39 | She could have taken the job in Dubai. |
| 40 | We could have bought the red car. |
Negatives and Questions
| No. | Sentence |
|---|---|
| 41 | I couldn’t sleep last night. |
| 42 | He couldn’t find his keys. |
| 43 | They couldn’t come to the party. |
| 44 | She couldn’t understand the question. |
| 45 | We couldn’t see anything in the dark. |
| 46 | Could you hear the teacher? |
| 47 | Could she drive when she was eighteen? |
| 48 | Could they finish the work on time? |
| 49 | Where could I buy a ticket? |
| 50 | Why couldn’t you call me? |
Can vs Could
Can and could are close, but they are not the same. Could is often more polite, and it can talk about the past.
| Idea | Can | Could |
|---|---|---|
| Ability now | I can swim. | Not used |
| Ability in the past | Not used | I could swim as a child. |
| Request | Can you help me? | Could you help me? (more polite) |
| Possibility | It can be cold here. | It could be cold tomorrow. |
Check your answer
Common Mistakes
| Common mistake | Better sentence | Why |
|---|---|---|
| I could to swim. | I could swim. | Do not use to after could. |
| She could went home. | She could go home. | Use the base verb after could. |
| He coulds run fast. | He could run fast. | Could never takes -s. |
| Do you could help me? | Could you help me? | Do not use do with could. |
| I could not to sleep. | I could not sleep. | Do not use to after could not. |
Practice: Exercises on Could
Exercise 1: Choose the Correct Word
Choose the correct form.
- She (could / coulds) play the piano at six.
- (Could / Do) you open the door, please?
- I couldn’t (to find / find) my bag.
- We could (went / go) to the beach.
- He could (speak / speaking) French as a child.
Show answers for Exercise 1
- Could (no -s)
- Could (a polite question)
- Find
- Go
- Speak
Exercise 2: Name the Use
Write the use of could in each sentence: past ability, polite request, possibility, suggestion or past chance.
- Could you pass the salt, please?
- I could run fast when I was young.
- It could snow tonight.
- We could go to the cinema.
- You could have called me.
Show answers for Exercise 2
- Polite request
- Past ability
- Possibility
- Suggestion
- Past chance
Exercise 3: Correct the Mistake
Each sentence has one mistake. Write the correct sentence.
- I could to swim at five.
- Do you could help me?
- She could went to school.
- He coulds read very well.
- They couldn’t to come.
Show answers for Exercise 3
- I could swim at five.
- Could you help me?
- She could go to school.
- He could read very well.
- They couldn’t come.
Quiz: Test Yourself
- What is the formula for could?
- Which sentence is a polite request?
- Which sentence shows ability in the past?
- Which sentence is correct?
- What is the negative form of could?
- Which sentence gives a suggestion?
- What does could have + past participle show?
- Which question is correct?
- Which word is more polite for a request?
- Which sentence is about possibility?
Key Takeaways
- Use could + base verb. Never add -s or to.
- Could shows past ability, polite requests, possibility and suggestions.
- The negative is could not or couldn’t.
- Could have + past participle shows a past chance.
- Could is more polite than can in requests.
Frequently Asked Questions
What does could mean?
Could is a modal verb. We use it for past ability, polite requests, possibility and suggestions. For example: Could you help me, please?
What is the structure of could?
Use subject + could + base verb. For example: She could swim. The negative is could not or couldn’t, and the question is Could + subject + base verb.
What is the difference between can and could?
Can talks about ability now. Could talks about ability in the past and is more polite in requests. For example: Could you help me?
Can we use could for the future?
Yes, for possibility and suggestions. For example: It could rain tomorrow. We could go to the beach on Sunday.
What does could have mean?
Could have + past participle shows a chance in the past that did not happen. For example: She could have won the race, but she fell.
Is could the past of can?
Could is the past form of can for ability, such as I could swim as a child. But could also has other uses that are not about the past, such as polite requests and suggestions.
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