UK:*UK and possibly other pronunciationsUK and possibly other pronunciations/ˈnəʊ/US:USA pronunciation: IPA and respellingUSA pronuncation: IPA/noʊ/ ,USA pronunciation: respelling(nō; Scot.nō, nou)

Inflections of 'know' (v): (⇒ conjugate)
v 3rd person singular
v pres pverb, present participle: -ing verb used descriptively or to form progressive verb--for example, "a singing bird," "It is singing."
v pastverb, past simple: Past tense--for example, "He saw the man." "She laughed."
v past pverb, past participle: Verb form used descriptively or to form verbs--for example, "the locked door," "The door has been locked."
WordReference Collins English Usage © 2020
awareness of facts
If you know that something is true, you are aware that it is true. The past tense of know is knew. The -ed participle is known.
I knew that she had recently graduated from law school.
I should have known that something was seriously wrong.
Be careful
Don't use a progressive form with know. Don't say, for example, ‘I am knowing that this is true’. You say ‘I know that this is true’.
‘I know’
If someone tells you a fact that you already know, or if they say something and you agree, you say ‘I know’.
‘That’s not their fault, Peter.' – ‘Yes, I know.’
‘This pizza is great’ – ‘I know.’
In American English you can also say ‘I know it’ in this situation. However, this often indicates that you are angry or annoyed.
‘The speed limit here is 35.’ – ‘Yeah, I know it.’
If you say that you will let someone know something, you mean that you will give them some information when you receive it, or if you receive it.
I'll find out about the car and let you know what's happened.
Let me know if she calls.
acquaintance and familiarity
If you know a person, place, or thing, you are acquainted with them or are familiar with them.
Do you know David?
He knew London well.
Do you know the poem ‘Kubla Khan’?
‘get to know’
If you want to say that someone gradually becomes acquainted with a person or gradually becomes familiar with a place, you say that they get to know the person or place.
I got to know some of the staff quite well.
I really wanted to get to know America.
Be careful
Don't use know without get to to mean ‘become acquainted with’.
‘know how to’
If you know how to do something, you have the necessary knowledge to do it.
No one knew how to repair it.
Do you know how to drive?
Don't say that someone ‘knows to’ do something.
'know' also found in these entries:

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