know
1 Americanverb (used with object)
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knows,
present (3rd person singular)
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knew,
past
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known,
past participle
-
knowing
present participle
-
to perceive or understand as fact or truth; to apprehend clearly and with certainty.
I know the situation fully.
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to have established or fixed in the mind or memory.
to know a poem by heart; Do you know the way to the park from here?
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to be cognizant or aware of.
I know it.
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be acquainted with (a thing, place, person, etc.), as by sight, experience, or report.
to know the mayor.
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to understand from experience or attainment (usually followed by how before an infinitive).
to know how to make gingerbread.
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to be able to distinguish, as one from another.
to know right from wrong.
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Archaic. to have sexual intercourse with.
verb (used without object)
-
knows,
present (3rd person singular)
-
knew,
past
-
known,
past participle
-
knowing
present participle
-
to have knowledge or clear and certain perception, as of fact or truth.
-
to be cognizant or aware, as of some fact, circumstance, or occurrence; have information, as about something.
noun
idioms
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know the ropes, to understand or be familiar with the particulars of a subject or business.
He knew the ropes better than anyone else in politics.
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in the know, possessing inside, secret, or special information.
noun
verb
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(also intr; may take a clause as object) to be or feel certain of the truth or accuracy of (a fact, etc)
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to be acquainted or familiar with
she's known him five years
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to have a familiarity or grasp of, as through study or experience
he knows French
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(also intr; may take a clause as object) to understand, be aware of, or perceive (facts, etc)
he knows the answer now
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(foll by how) to be sure or aware of (how to be or do something)
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to experience, esp deeply
to know poverty
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to be intelligent, informed, or sensible enough (to do something)
she knew not to go home yet
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(may take a clause as object) to be able to distinguish or discriminate
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archaic to have sexual intercourse with
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I have an idea
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to know how one thing or things in general work
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informal a parenthetical filler phrase used to make a pause in speaking or add slight emphasis to a statement
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things are uncertain
noun
Usage
What are other ways to say know? To know something is to perceive or understand it as fact or truth. When should you use this verb over understand or comprehend? Find out on Thesaurus.com.
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
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knowsimple
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knowssimple
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have knownperfect
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has knownperfect
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am knowingprogressive
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are knowingprogressive
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is knowingprogressive
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have been knowingperfect progressive
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has been knowingperfect progressive
Past
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knewsimple
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had knownperfect
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was knowingprogressive
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were knowingprogressive
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had been knowingperfect progressive
Future
Etymology
Origin of know
First recorded before 900; Middle English knowen, knawen, Old English gecnāwan; cognate with Old High German -cnāhan, Old Norse knā “to know how, be able to”; akin to Greek gignṓskein, Latin (g)nōscere, Sanskrit jñātá “known”; see also can 1, gnostic
Explanation
To know something means to have a piece of information or a certain understanding of something. If someone tells you their phone number and you remember it, you know. There's a reason you can find the word know in the word knowledge — to know is to have knowledge about something, to be familiar with an idea, or to recognize someone. If you're "in the know," you have information that is only known to a select group of people. But be careful — to know someone in the Biblical sense means that you're having sexual relations with them.
Vocabulary lists containing know
Words from "Miss Alaineus, A Vocabulary Disaster" by Debra Frasier
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Spelling Practice 1, Unit 3
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Spelling Practice, Unit 8
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
TikTok said while certain content can't be promoted on the For You feed, it's transparent about posts that fall into this category and lets creators know so they can appeal.
From BBC ● Oct. 16, 2026
“And I just want you to know my thoughts are with you.”
From The Wall Street Journal ● Oct. 16, 2026
Yet on the stump you might not know she’s ever heard of Chuck Schumer.
From The Wall Street Journal ● Oct. 15, 2026
“I don’t know if now is the time. I don’t know that it’s hard to figure out kind of what happened.”
From Los Angeles Times ● Oct. 15, 2026
I know she’s trying to put on a brave face.
From "Split the Sky" by Marie Arnold
“No one knows what’s going to happen tomorrow and the ensuing days,” Roberts said.
From Los Angeles Times ● Oct. 14, 2026
“Who knows, maybe I will fall in love with a desk job,” Avi says.
From The Wall Street Journal ● Oct. 14, 2026
And additional thanks to Lorne Michaels, who knows a ratings/headlines cow when he sees one, even if he doesn’t want to house him in his own barn at the end of the night.
From Salon ● Oct. 14, 2026
She knows all too well how crucial a support network is after her twin boys, George and Henry, were stillborn in 2018.
From BBC ● Oct. 13, 2026
“Miss ten Boom, I am a Jew. Who knows when they will come to take me away? My wife too—although she is a Gentile—is in danger because of her marriage.”
From "The Hiding Place" by Corrie ten Boom
The partner “whom she knew, or believed she knew” is, Julia thinks, “not altogether the same man” as the Ryan with whom she now lives.
From The Wall Street Journal ● Oct. 15, 2026
“I knew it was going to be his moment,” says Ambrossi.
From Los Angeles Times ● Oct. 15, 2026
I asked whether he knew the vigil had included testimonies from families in Gaza, which Lenkinski said the protesters had drowned out.
From Slate ● Oct. 15, 2026
"We already knew that tetraploidy can make cells more tumorigenic, but now we know that if you incorporate the size of the cells, it can be more predictive of tumorigenic potential," Cimini said.
From Science Daily ● Oct. 15, 2026
Maggie knew she wouldn’t quite be able to mimic Bernadette’s motions.
From "Legendary Frybread Drive-In" by Cynthia Leitich Smith
Horton was known as the more outgoing and gregarious of the pair, but both sisters were described as being inquisitive, opinionated, fiercely loyal and competitive.
From Los Angeles Times ● Oct. 16, 2026
The character of Lisa Molinari has undergone a transformation from the original Marvel comic book character - known as Coat of Arms - who gains extra arms and weapons from a mystical coat.
From BBC ● Oct. 15, 2026
Finding well-off husbands is Elinor and Marianne’s only hope of returning to something like the comfort they have known.
From The Wall Street Journal ● Oct. 15, 2026
Rockstar posted a new trailer online for "GTA VI" featuring a song from "original score composers Justice", who are best known for their work during the late "French Touch" electro wave of the early 2000s.
From Barron's ● Oct. 15, 2026
He hadn’t known he was capable of Recollecting with living animals.
From "The Undead Fox of Deadwood Forest" by Aubrey Hartman
"There's a lot of evidence about Shell knowing as early as in the 1960s" that fossil fuels contributed to global warming, said Madeleine Lynch, a campaigner on the "Odette case."
From Barron's ● Oct. 15, 2026
But he has a knack for knowing precisely where and when to shift from one topic to the next to maintain the momentum of the narrative.
From The Wall Street Journal ● Oct. 14, 2026
Start by knowing your numbers, like your blood pressure, cholesterol and blood sugar.
From MarketWatch ● Oct. 13, 2026
"Scammers exploit the fact that roofs are out of sight and reach, knowing most people can't easily inspect the work themselves," she said.
From BBC ● Oct. 11, 2026
I tried to sound casual, but apparently I’d never actually sounded casual in my life, because Grandma’s face broke into a knowing smile.
From "Bye Forever, I Guess" by Jodi Meadows
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Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
