know
Formsknows, knowing, knew, known
Formsknows, knowing, knew, known
- 1To have facts or information in your mind and be sure they are true.
Did you know they were getting divorced?
My grandmother knows the phone numbers of all her neighbors by heart.
UsageSay I know (not
incorrect: I'm knowing), often with no that after it.Similarrealize, understand
Note
- 2To be familiar with a person, place or thing because you have met or seen them before.
Ask Tom for directions. He knows this city well.
I know this park. We came here last summer.
UsageSay get to know someone when you start to know them.
Note
- 3To call someone or something by a certain name or title, mostly in the form be known as.
At school he is known as Red because of his hair.
Her friends know her as Bea, not Beatrice.
UsagePut as before the name: known as Red. Use known for with what makes someone famous.
Similarcall
- 4To think of someone or something mainly because of a thing they are famous for, mostly as be known for.
Our city is known for its very hot summers.
Most kids know her for her funny cooking videos.
UsageAfter for, use a noun or an -ing form: known for its bread, known for making bread.
- 5To have learned something and be able to use or do it, like a language, game or song.
I know the song by heart and can play it on the guitar.
My little brother knows how to ride a bike without training wheels now.
UsageSay I know how to swim, and I know French.
Note
Less common meanings
- 6To recognize someone or something, or tell it apart from others.
Even a small child knows right from wrong.
I wouldn't know one twin from the other.
UsageSay know right from wrong.
Similarrecognize, identify, distinguish
Note
- 7To have gone through or lived through something.
My parents knew hard times when they first moved to this city.
Few villages know such hardship as this one has.
Similarexperience, see, undergo, endure, suffer
- 8Knowing secret or special information, as in 'people in the know'.
Only a few people are in the know.
Those in the know bought early.
UsageUsually in be in the know or keep someone in the know.
- 9A polite way of saying to have sex with someone.
Wait a second. Are you… attempting to know me?
2003, Garland Testa, 19:37 from the startHere, know means to have sex with someone.Now Gerald had never thought of her having a mother. Then there must have been a father, too, some time. And Miss Wilmarth existed because two people once had loved and known. It was not a thought to dwell upon.
1939, Dorothy Parker, “Horsie,”Here, known means had sex with each other.Note
- 10To have a record of something, used about a database or search engine.
The site doesn't know that name.
Our database knows about two million products.
Similarrecognize
- 11In philosophy, to hold a belief that counts as knowledge, traditionally one that is true and backed by good reasons.
On this account, to know is to have a belief that is both true and justified.
Can we really know anything about the external world?
Note
- 12In Singapore English, a word at the end of a sentence meaning remember this.
Remember to bring your jacket tomorrow, the bus is very cold, know.
I already finished all my homework before dinner, know!
Note
Showing meanings only.
Practice
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Origins
In Old English the word was "cnāwan", and it meant to know, perceive, or recognize. It comes from older Germanic words and, before that, from a very old root that meant "to know".
Checked 1 Nov 2026 · 4 facts
- The word descends from Old English cnāwan. en.wiktionary.org
- Old English cnāwan meant to know, perceive, or recognize. en.wiktionary.org
- The word descends through earlier Germanic forms. en.wiktionary.org
- Its earlier root meant “to know”: Proto-Indo-European *ǵneh₃-. en.wiktionary.org
This is a short form of the phrase "you know".
Checked 1 Nov 2026 · 1 fact
- This sense of know is a short form of you know. en.wiktionary.org