Can or Could
The Modal Can
We use the modal can to make general statements about what is possible:
- It can be a very painful proceure
- It can be very cold in winter.
We use the negative can’t or cannot to show that something is impossible:
- that can’t be possible
- That can’t be true.
We use can to talk about someone’s skill or general abilities:
- She can speak several languages.
- She can play soccer very well
We use can to ask for permission to do something:
- Can I eat these cookies?
- Can I ask a question, please?
We use can to give permission:
- You can start working again
- You can go home now if you like
We use can I … to make offers
- Can I buy a drink or coffee?
- Can I help you?
The Modal Could
We use could as the past tense of can:
- It could be very hot in the summer.
- You could lose your money if you contunue gambling
We use could to show that something is possible in the future, but not certain:
- If we don’t hurry we could be late
- If we don’t do the homework, we could fail the course
We use couldn’t/could not to talk about the past:
- We knew it could not be true.
- He was obviously joking. He could not be serious.
We use could to talk about past time:
- She could speak three languages
- They couldn’t dance electronic music really well
could is more formal and polite than can:
- Could I ask a question please?
- Could we go home now?
We use could you and as a polite way of telling or asking someone to do something:
- Could you take a message please?
- Could I have my bill please?