know
1 Americanverb (used with object)
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knows,
present (3rd person singular)
-
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:
Fieri testified during the trial that he didn’t know Wade and didn’t give him permission to take his car out of the San Francisco dealership.
From Los Angeles Times ● Sep. 14, 2026
Nor do we know, because the government hasn't decided yet, what relocating - residency - would look like legally.
From BBC ● Sep. 14, 2026
“The idea that we just throw computers and screens and AI models in front of kids runs in complete contrast to what we know actually works in the classroom.”
From The Wall Street Journal ● Sep. 14, 2026
It’s not that you ever really needed to know what happens inside of your dishwasher, but the point is that now you can know.
From Slate ● Sep. 14, 2026
“You know Arlo—he just has to be dramatic. He’ll be fine.”
From "Split the Sky" by Marie Arnold
To help kick off the 78th Emmy Awards Monday, Mariska Hargitay tapped a friend who knows something about assists: New York Knicks point guard Jalen Bruson.
From Los Angeles Times ● Sep. 15, 2026
Szares knows about Notre Dame’s kicking tradition from looking at the alumni board of top football players in the gym.
From Los Angeles Times ● Sep. 13, 2026
The passenger train line between Warsaw and Kyiv is a a main travel route for civilians, as the Kremlin knows.
From The Wall Street Journal ● Sep. 13, 2026
This self-acceptance is irresistible to some and a threat to others, as Dr. Suwinyattichaiporn knows all too well.
From Salon ● Sep. 13, 2026
But I can tell he knows I’m here.
From "Will’s Race for Home" by Jewell Parker Rhodes
“We knew the best landlord we could possibly have would be ourselves,” Capital Group Chief Executive Mike Gitlin said in April.
From Los Angeles Times ● Sep. 14, 2026
A jogger who knew Moselakgomo through their running club told the BBC the discovery of the five bodies was "very scary".
From BBC ● Sep. 14, 2026
And he knew they were bound to be unpopular.
From BBC ● Sep. 13, 2026
I knew I would never be Sandy Koufax, but I thought that I could at least be one of nine on a student team—not a star, but a dependable utility player.
From The Wall Street Journal ● Sep. 13, 2026
The one thing we knew for sure—the new generation of chiefs had decided it was time for Fireball to die, and nothing I, or anyone else, said was going to have any impact.
From "Legendary Frybread Drive-In" by Cynthia Leitich Smith
Taken together, the evidence suggests that some of the earliest known plague outbreaks may already have been as deadly as later historical epidemics, particularly for children.
From Science Daily ● Sep. 15, 2026
It’s hard to believe that some of television’s finest actors — industry veterans known for iconic shows and critically acclaimed performances — have yet to receive the industry’s highest honor.
From Los Angeles Times ● Sep. 14, 2026
Sweeney, 29, is known for her role in the television series Euphoria and the films Anyone But You and The Housemaid.
From BBC ● Sep. 14, 2026
The U.S. has provided Jews with the most welcoming home, apart from Israel, that they have known through their long diaspora.
From The Wall Street Journal ● Sep. 14, 2026
The wolves somehow had not known I was there.
From "Woodsong" by Gary Paulsen
“Anyone knowing Plaschke’s penchant for delivering laughable predictions has an easy way to make money: Kalshi. The easiest money you’ll ever make.”
From Los Angeles Times ● Sep. 13, 2026
“Light’s got very limited exposure at the NFL level, so they obviously are trying to be as aggressive as they can, knowing the importance of that exposure,” said Certor CEO Jeremy Erspamer.
From The Wall Street Journal ● Sep. 13, 2026
Releasing a hurtling hunk of metal without knowing where it would go and what would happen is too likely to cause harm.
From Salon ● Sep. 12, 2026
For Reece, knowing his way around the maternity ward beforehand means he can be "more independent and able to support Sophy as her birthing partner".
From BBC ● Sep. 12, 2026
This place may not be real, but Mom’s reaction is: Her relief at seeing Maggie is soured just by Maggie knowing a single Chickasaw thing.
From "Legendary Frybread Drive-In" by Cynthia Leitich Smith
Definitions 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.
