can

canmodal verb

Can is used to talk about what is possible, what someone is able to do, and what is allowed.

1. be able toused to say that someone or something is able to do something

   The most common use of can. It talks about a skill or the power to do something now. For general ability in the past, use could: she could swim by the age of five. For one particular action that was actually completed, use was able to or managed to, not could: she was able to open the door, not she could open the door. For other tenses and forms, use be able to: I have never been able to swim.

   verb + bare infinitive [V + inf]

   • Ana can swim very well. V + inf
   • Can you lift this box on your own? V + inf
   • A newborn baby cannot see clearly. V + inf

   Compare could (could is the past of can and a more polite or less certain form); able

2. be possibleused to say that something is possible or sometimes happens

   This talks about what is possible in general or what happens from time to time, rather than about one certain event.

   verb + bare infinitive [V + inf]

   • It can get very cold here in winter. V + inf
   • Prices can change from day to day. V + inf
   • Too much sun can be harmful. V + inf

3. be allowedused to say that someone is allowed to do something

   Can gives or reports permission. Could and may are also used; may is more formal.

   verb + bare infinitive [V + inf]

   • You can leave once you have finished. V + inf
   • Can I borrow your umbrella? V + inf
   • Visitors can use the garden until dark. V + inf

   Compare may (may is a more formal way to give or ask permission)

4. requests and offersused to ask someone to do something or to offer help

   A very common, friendly way to make a request or an offer. Could is a little more polite.

   verb + bare infinitive [V + inf]

   • Can you pass the salt, please? V + inf (request)
   • Can I help you carry those bags? V + inf (offer)
   • Can you tell me the way to the market? V + inf (request)

5. with see, hear, feelused with verbs of the senses and the mind, such as see, hear, and understand, to talk about what someone is aware of at a certain moment

   English often adds can to verbs like see, hear, smell, feel, and understand to talk about what someone is aware of right now: I can see the sea means the sea is in view at this moment. The plain present is also possible and often sounds natural too, especially in a general statement: I see what you mean.

   verb + bare infinitive [V + inf]

   • I can see the mountains from my window. V + inf
   • Can you hear that strange noise? V + inf
   • I can't understand this word. V + inf

   For translators (sense 5)

   Grammar trap With verbs of the senses and the mind (see, hear, smell, feel, understand), English often adds can for something perceived or understood right now: I can hear you. The plain present is also common, especially in a fixed reaction such as I hear you (I understand how you feel).

6. not possibleused in the negative to say that something is not possible or is very unlikely to be true

   Can't or cannot shows that the speaker is sure, from what they know, that something is false. Must works the same way for the positive, to say the speaker is sure something is true.

   verb + bare infinitive [V + inf]

   • That can't be true. V + inf
   • She can't be over thirty; she looks so young. V + inf
   • You can't be serious! V + inf

   Compare must (must is the positive counterpart: sure that something is true, not false)

   For translators (sense 6)

   Grammar trap This use is always negative (can't, cannot); the affirmative counterpart of the same idea is must, not can: it must be true, not it can be true, to say the speaker is sure.

See also could; may (may for formal permission and possibility); able (be able to fills the tenses can lacks)