Can, could and (be) able to
We use can to say that something is possible or that somebody has the ability to do something, but can has only two forms, can (present) and could (past). So sometimes it is necessary to use (be) able to... Compare:
I can't sleep but I haven't been able to sleep recently. (can has no present perfect)
Tom can come tomorrow but Tom might be able to come tomorrow. (can has no infinitive)
1. Complete the sentences with can/can't/could/couldn't + one of these verbs:
Come cat hear run sleep wait
1. I'm afraid I _can't come_ to your party next week.
2. When Tim was 16, he was a fast runner. He ___________ 100 meters in 11 seconds.
3. Are you in a hurry?' 'No, I've got plenty of time. I ____________.'
4. I was feeling sick yesterday. I ____________ anything.
5. Can you speak up a bit? I ____________ you very well.
6. 'You look tired.' 'Yes, I ____________ last night,'
2. Complete the sentences using could, couldn't or was/were able to.
1. My grandfather was a very clever man. He ____________speak five languages.
2. I looked everywhere for the book but I ____________find it.
3. They didn't want to come with us at first but we ____________persuade them.
4. Laura had hurt her leg and ____________ walk very well.
5. Sue wasn't at home when I phoned but I ____________ contact her at her office.
6. I looked very carefully and I ____________ see a figure in the distance.
7. I wanted to buy some tomatoes. The first shop I went to didn't have any but I ____________ get some in the next shop.
8. My grandmother loved music. She ____________ play the piano very well.
9. A girl fell into the river but fortunately we ____________ rescue her.
10. I had forgotten to bring my camera so I ____________ take any photographs.
Must and can't
We use must to say that we feel sure something is true:
You've been travelling all day. You must be tired.
We use can't to say that we feel sure something is not possible:
You've just had lunch. You can't be hungry already.
For the past we use must have (done) and can't have (done).
1. Put in must or can't.
2. You've been travelling all day. You must be very tired.
3. That restaurant ____________ be very good. It's always full of people.
4. That restaurant ____________ be very good. It's always empty.
5. You're going on holiday next week. You ____________ be looking forward to it.
6. It rained every day during their holiday, so they __________ have had a very nice time.
7. Congratulations on passing your exam. You ____________ be very pleased.
8. You got here very quickly. You ____________ have walked very fast.
9. Bill and Sue go away on holiday very often, so they _______ be short of money.
2. Read the situations and use the words in brackets to write sentences with must have and can't have.
1. The phone rang but I didn't hear it. (I/asleep)
2. Jane walked past me without speaking. (she/see/me)
3. The jacket you bought is very good quality. (it/very expensive)
4. I haven't seen the people next door for ages. (they/go away)
5. I can't find my umbrella. (I/leave/it in the restaurant last night)
6. Don passed the exam without studying for it. (the exam/very difficult)
7. She knew everything about our plans. (she/listen/to our conversation)
8. Fiona did the opposite of what I asked her to do. (she/understand/what I said)
9. When I woke up this morning, the light was on. (I/forget/to turn it off)
10. The lights were red but the car didn't stop. (the driver I see/the red light)
May and might
We use may or might to say that something is a possibility. Might is used when it is considered less likely.
You are looking for Bob. Nobody is sure where he is but you get some suggestions.
You: Where's Bob? He may be in his office. (= perhaps he is in his office)
For the past we use may have (done) or might have (done):
A: I wonder why Kay didn't answer the phone. B: She may have been asleep. Sometimes could has a similar meaning to might:
The phone's ringing. It could be Tim. (= it might be Tim)
1. Read the situations and make sentences from the words in brackets. Use may or might.
1. I can't find George anywhere. I wonder where he is. (he/go/shopping)
2. I'm looking for Helen. Do you know where she is? (she/watch/TV/in her room)
3. I can't find my umbrella. Have you seen it? (it/be/in the car)
4. Why didn't Tom answer the doorbell? I'm sure he was in the house at the time.
(he/be/in the bath)
2. Complete the sentences using might + one of these verbs:
Bite break need rain slip wake
1. Take an umbrella with you when you go out. It ____________ rain later.
2. Don't make too much noise. You ____________ the baby.
3. Be careful of that dog. It ____________ you.
4. I don't think we should throw that letter away. We ____________ it later.
5. Be careful. The footpath is very icy. You ____________
6. I don't want the children to play in this room. They ____________ something.
Must and have to
We use must and have to to say that it is necessary to do something.
Oh, it's later than I thought. I must go. or I have to go.
You can use must to talk about the present or future, but not the past:
We must go now. We must go tomorrow. (but not 'We must go yesterday')
You can use have to in all forms.
Mustn't and don't have to are completely different:
You mustn't do something = it is necessary that you do not do it (so, don't do it):
You must keep it a secret. You mustn't tell anyone. (= don't tell anyone)
I promised I would be on time. I mustn't be late. (= I must be on time)
You don't have to do something = you don't need to do it (but you can if you want):
I'm not working tomorrow, so I don't have to get up early.
Don’t have to =needn’t
1. Make questions with have to.
1. I had to go to hospital last week. Why did you have to go to hospital?
2. I have to get up early tomorrow. Why --- early?
3. Ann has to go somewhere now. Where --- she ---.
4. George had to pay a parking fine yesterday. How much ---.
5. I had to wait a long time for the bus. How long ---.
2. Complete the sentences with must, mustn't or needn't.
1. We haven't got much time. We _must_ hurry.
2. We've got plenty of time. We ____________ hurry.
3. We have enough food at home so we ____________ go shopping today.
4. Jim gave me a letter to post. I ____________ remember to post it.
5. Jim gave me a letter to post. I ____________ forget to post it.
6. There's plenty of time for you to make up your mind. You ___________ decide now.
7. You ____________ wash those tomatoes. They've already been washed.
8. This is a valuable book. You __________ look after it carefully and you ____________lose it.
1. For each situation write a sentence with should or shouldn't + one of the following.
go away for a few days go to bed so late look for another job put some pictures on the walls take a photograph use her car so much
1. (Liz needs a change.) _She should go away for a few days._
2. (My salary is very low.) You ____________
3. (Jack always has difficulty getting up.) He ____________
4. (What a beautiful view!) You____________
5. (Sue drives everywhere. She never walks.) She ____________
6. (Bill's room isn't very interesting.) ____________
2. Read the situations and write sentences with should/shouldn't. Some of the sentences are past and some are present.
1. I'm feeling sick. I ate too much. _I shouldn't have eaten so much._
2. That man on the motorbike isn't wearing a helmet. That's dangerous.
He _should be wearing a helmet._
3. When we got to the restaurant, there were no free tables. We hadn't reserved one. We ____________
4. The notice says that the shop is open every day from 8.30. It is 9 o'clock now but the shop isn't open yet. ____________
5. The speed limit is 30 miles an hour, but Catherine is doing 50.
6. I went to Paris. A friend of mine lives in Paris but I didn't go to see him while I was there.
When I saw him later, he said: You ____________
7. I was driving behind another car. Suddenly, the driver in front stopped without warning and I drove into the back of his car. It wasn't my fault ____________
8. I walked into a wall. I wasn't looking where I was going. I____________