Meaning of “know” - Learner’s Dictionary

know

verb us uk /nəʊ/ past tense knew, past participle known
Extra Examples
You don't happen to know her phone number, do you?I don't know where he is.What do you know about the history of jazz?Hold your hand up if you know the answer.Do you know how long the film is?
HAVE INFORMATION [ I, T ]

A1 to have knowledge or information about something in your mind:

"How old is she?" "I don't know."
Andrew knows a lot about computers.
[ + question word ] Do you know where the station is?
[ + (that) ] He knew that she was lying.
Do your parents know you smoke?
BE FAMILIAR WITH [ T ]

B1 to be familiar with a person, place, or thing because you have met them, been there, used it, etc before:

I've known Tim since primary school.
I grew up in Brussels so I know it well.
Since moving to London, I've got to know (= become familiar with) some nice people.
BE ABLE [ T ]

A2 to be able to do something:

[ + question word ] Do you know how to ski?
I only know (= understand and speak) a little Spanish.
let sb know

A2 to tell someone something:

Let me know if you're going to the party.
GUESS CORRECTLY [ T ]

to guess something correctly:

I knew she'd arrive late.
I should have known he wouldn't come.
UNDERSTAND [ I, T ]

to understand and agree with someone:

I know what you mean about Pete - I wouldn't trust him at all.
be known as sth

B1 to be called something:

California is also known as the Sunshine State.
have known sth

to have had experience of something:

I've never known the weather be so hot.
know better (than to do sth)

B2 to have the intelligence or judgment not to do something:

She should have known better than to eat so much. No wonder she feels sick now.
I know

B2 used when you agree with something someone has just said:

"It's a lovely day, isn't it?" "I know - let's hope it lasts."

B1 used when you have an idea:

I know - let's go to Helen's house.
you know

used to emphasize that someone does know what you are referring to:

You know, he's the one with curly hair.

B1 something that you say while you are thinking what to say next:

It's, you know, supposed to be a surprise.

B1 used to emphasize what you are saying:

I'm not an idiot, you know.
as far as I know

B2 used to say that you think something is true, but cannot be sure:

As far as I know, he's never been in prison.
you never know

B2 used to say that something could be possible although it does not seem likely:

You never know - you might win the lottery.
before you know it

very soon:

We'll be there before you know it.
→ See also know sth inside out , learn/know the ropes , know your stuff

(Definition of “know verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)