Grammar Lessons: Can or Could

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. 
  • It can be very expensive but it is worth it
  • You can easily lose your job acting like that

We use the negative can’t or cannot to show that something is impossible:

  • that can’t be possible
  • That can’t be true.
  • That can’t happen
  • You can’t be serious

We use can to talk about someone’s skill or general abilities: 

  • She can speak several languages.
  • She can play soccer very well
  • She can sing better than I do
  • He can’t dance really well

We use can to ask for permission to do something: 

  • Can I eat these cookies?
  • Can I ask a question, please?
  • Can I drive your car?
  • Can I have a word with you?

We use can to give permission:

  • You can start working again
  • Students can travel free
  • You can go home now if you like
  • You can play whenever you want

We use can I … to make offers

  • Can I buy a drink or coffee?
  • Can I help you?
  • Can I get you something to eat?
Can or Could

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
  • She couldn’t phone you earlier

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
  • If they catch us, they could hurt us

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 ability to do something:

  • She could speak three languages
  • I tried but I couldn’t open the bottle
  • They couldn’t dance electronic music really well
  • I could speak german really well when I was in my 20’s

could is more formal and polite than can:

  • Could I ask a question please?
  • Could we go home now?
  • Could I tell you something?

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?
  • Could you open my door for me ?
  • Could you drive home please?