Can, could and be able to
The rule in short
How to talk about ability in the present, past and future, when could is right for the past, when you need was able to or managed to, and why be able to fills the gaps that can leaves.
| Time or position | Form | Example |
|---|---|---|
| present | can / can't + base verb | Anna can type very fast. |
| past, general ability | could / couldn't + base verb | I could read before I started school. |
| past, one success | was / were able to or managed to + base verb | The car broke down, but we managed to get home. |
| past, one failure | couldn't or wasn't / weren't able to + base verb | I couldn't open the window. |
| future | will be able to + base verb | You will be able to walk again in a month. |
| present perfect | have / has been able to + base verb | Tom hasn't been able to work this week. |
| after another verb | to be able to + base verb | I'd like to be able to sing. |
| after a preposition, or as a subject | being able to + base verb | She's afraid of not being able to finish. |
Able is an adjective, so it usually needs a form of be before it and to after it: I am able to, she was able to. Can and could never take to.
The rule for the past is the heart of this lesson. Could describes an ability someone had over a period of time: When I was a child, I could climb any tree. For one particular success, positive could usually sounds wrong to most speakers, so use was able to or managed to: The last bus had gone, but we were able to get a lift with a neighbour. Managed to adds the idea that it was difficult. In negative sentences there is no such problem: couldn't and wasn't able to are both fine for one failure.
There is one exception. With verbs of the senses and of the mind, such as see, hear, smell, feel, understand and remember, could is normal even for one moment: The moment the plane landed, I could see snow on the hills.
For the future, will be able to is the usual form for an ability you do not have yet. When you arrange something now for later, can is also possible: I can meet you tomorrow.
Examples
- Anna can speak Polish and Italian, but she can't drive.
- When Tom was young, he could run very fast.
- Anna couldn't ride a bike until she was ten.
- The road was closed, but we were able to find another way.
- After many tries, Tom managed to fix the old radio.
- In the dark room I could hear someone breathing.
- Anna will be able to drive alone after her test in June.
- I haven't been able to contact Tom since Monday.
- You need to be able to type quickly in this job.
- Being able to relax after work is important.
Lesson: “Can, could and be able to” (B1), Krumeto · https://krumeto.com/grammar/can-could-be-able-to · written for Krumeto with the help of AI tools · Worksheet: krumeto.com
Exercises
A. Choose the right form.
She hopes ___ come. → to be able to
- I'd like ________ drive one day. (to can / to be able to / can)
- Tom ________ come to work tomorrow. His car is broken. (won't be able to / won't can / doesn't can)
- We ________ visit Anna since she moved away. (haven't been able to / haven't could / can't)
- ________ to speak two languages is a big help at work. (Being able / Can / To can)
- Anna ________ play the violin when she was six. (could / can / has been able to)
- Will you ________ help me tomorrow? (be able to / can / could)
B. General ability or one success? Choose the right past form.
The bus was full, but we ___ get on. → managed to
- The shop had only one cake left, but Tom ________ buy it for Anna's birthday. (could / was able to)
- When Tom was a child, he ________ sleep anywhere. (can / could / will be able to)
- I lost my keys, but after ten minutes I ________ open the back door with a knife. (could / managed to)
- The music was so loud that I ________ hear what Anna was saying. (couldn't / can't / didn't can)
- When we got to the top of the hill, we ________ see the whole town. (could / can / were able)
- Anna dropped her ring into the sea, but amazingly she ________ get it back. (could / was able to / can)
C. Complete the sentences with a form of be able to and the verb in brackets.
They hope ___ (stay). → to be able to stay
- I'm sorry, but I won't ________ (come) to your party on Friday.
- Tom has broken his glasses, so he hasn't ________ (read) anything all day.
- Anna would love ________ (speak) Japanese.
- Tom is tired of not ________ (find) a parking space near his flat.
- The questions were hard, but most students ________ (answer) all of them.
- When the new bridge opens next year, people ________ (cross) the river in five minutes.
D. Rewrite the sentences as the brackets say.
We can't use the lift. (since Friday) → We haven't been able to use the lift since Friday.
- We managed to open the door. (use be able to)
- Tom couldn't find his phone. (use be able to)
- I can't concentrate. It started on Monday. (present perfect + since Monday)
- Can you send me the photos by Friday? (use will)
- Anna was able to carry the box herself. (use manage)
E. Put the words in order. Use all the words.
- Tom / hasn't / yet / been / a / flat / to / find / able
- we / English / able / work / be / to / speak / at / to / need
- managed / catch / we / the / last / bus / to
- the / be / party / to / able / you / come / to / will
- to / useful / very / being / able / cook / is
F. Correct the mistakes. Change only what is wrong. Two of the sentences are already right: keep them as they are.
- Tom broke his leg, so he will not can play on Saturday.
- Anna has could read since she was four.
- The trains weren't running, but in the end we could get a taxi.
- I want to can speak French better.
- When I lived in Spain, I could swim every day.
- We couldn't see anything, but we could hear the sea.
G. Match the beginnings and the endings.
- Sorry, I won't ____
- Anna has never ____
- Anna hates the idea of not ____
- When she was five, Anna ____
- Were you ____
- a) could already count to a hundred.
- b) able to find the station?
- c) be able to call you tonight.
- d) been able to whistle.
- e) being able to drive.
Answer key
A. Can has only two forms, can and could. After will, have, to or a preposition, and at the start as a subject, use a form of be able to.
- to be able to
- won't be able to
- haven't been able to
- Being able
- could
- be able to
B. Positive could is for a general ability in the past. For one success, use was / were able to or managed to. Couldn't is fine for both. With see, hear and other sense verbs, could is fine for one moment.
- was able to
- could
- managed to
- couldn't
- could — With see, hear and other sense verbs, could is normal even for one moment.
- was able to
C. Be able to can follow will, have, to and prepositions: won't be able to, hasn't been able to, to be able to, of being able to. In the past, use was / were able to.
- be able to come
- been able to read
- to be able to speak
- being able to find
- were able to answer
- will be able to cross / should be able to cross
D. Couldn't = wasn't able to. For one success, managed to = was able to; positive could is only for a general ability. The future is will be able to; the present perfect is have been able to.
- We were able to open the door.
- Tom wasn't able to find his phone.
- I haven't been able to concentrate since Monday. / Since Monday I haven't been able to concentrate.
- Will you be able to send me the photos by Friday?
- Anna managed to carry the box herself. / Anna managed to carry the box by herself.
E. Build the ability form in one block (will be able to, hasn't been able to, need to be able to, managed to) and put the base verb straight after to.
- Tom hasn't been able to find a flat yet. / Hasn't Tom been able to find a flat yet?
- We need to be able to speak English at work. / At work we need to be able to speak English.
- We managed to catch the last bus.
- Will you be able to come to the party? / You will be able to come to the party.
- Being able to cook is very useful. / Is being able to cook very useful?
F. Can has only can and could. After will, have and to, use be able to. For one success in the past, use was able to or managed to. Could is fine for a general past ability and with sense verbs.
- Tom broke his leg, so he will not be able to play on Saturday. / Tom broke his leg, so he can't play on Saturday.
- Anna has been able to read since she was four. / Anna's been able to read since she was four.
- The trains weren't running, but in the end we were able to get a taxi. / The trains weren't running, but in the end we managed to get a taxi.
- I want to be able to speak French better.
- When I lived in Spain, I could swim every day. (✓)
- We couldn't see anything, but we could hear the sea. (✓)
G. Won't and to take be able to, have takes been able to, a preposition takes being able to, and could needs no to.
- 1 c · 2 d · 3 e · 4 a · 5 b
Lesson: “Can, could and be able to” (B1), Krumeto · https://krumeto.com/grammar/can-could-be-able-to · written for Krumeto with the help of AI tools · Worksheet: krumeto.com