know
1 Americanverb (used with object)
-
knows,
present (3rd person singular)
-
knew,
past
-
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.
-
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.
-
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
-
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
-
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
-
knewsimple
-
had knownperfect
-
was knowingprogressive
-
were knowingprogressive
-
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:
Make sure you know how much you owe.
From MarketWatch ● Oct. 22, 2026
Here’s what we know so far about ‘Heated Rivalry’ Season 2, which hits HBO Max in spring 2027.
From Los Angeles Times ● Oct. 22, 2026
“I know you lost a year of your life, but you’ve done very well here,” a Russian investigator tells Mr. Gershkovich as his release nears.
From The Wall Street Journal ● Oct. 22, 2026
"So our focus is on the contact tracing and ensuring that we know exactly where those contacts are."
From Barron's ● Oct. 22, 2026
I know she’s trying to put on a brave face.
From "Split the Sky" by Marie Arnold
Like when you see shows on TV, like “Jerry Springer,” everything’s written, so he knows what’s gonna happen.
From Los Angeles Times ● Oct. 22, 2026
The senators sent a letter to Google CEO Sundar Pichai seeking information on what the company knows about its AI products’ impact on children.
From The Wall Street Journal ● Oct. 21, 2026
How else can you explain a verse that is 90% throat-clearing and preemptive dodges of the backlash he knows is coming?
From Salon ● Oct. 21, 2026
"Everyone knows about us because of Ali G, and many of us wear that as a badge of pride," he says.
From BBC ● Oct. 20, 2026
Arlo’s eyes grow wide as he looks from Candace to Aunt J. He knows something’s up.
From "Split the Sky" by Marie Arnold
When Doncic drove, Kessler knew to step up.
From Los Angeles Times ● Oct. 22, 2026
"Essentially we just discussed family matters," Aris said, adding: "We knew the phone call would be recorded, so we didn't talk about anything sensitive."
From Barron's ● Oct. 22, 2026
It added that it was unclear how actors knew about the vulnerabilities.
From BBC ● Oct. 22, 2026
Mignon, her family and friends saw what was happening in Germany, and they knew that antisemitism was rising in Austria.
From The Wall Street Journal ● Oct. 21, 2026
It was supposed to be for the Future, but I never knew why the Future needed it.
From "Legendary Frybread Drive-In" by Cynthia Leitich Smith
When the money runs out, they kick the patients out without support or referrals, regardless of whether or not they have recovered—a practice known as “patient dumping” or “curbing.”
From The Wall Street Journal ● Oct. 22, 2026
Jenna Ortega plays Klara, the B1 model of a robot companion known as Artificial Friend, or AF.
From Los Angeles Times ● Oct. 22, 2026
The changes, known as the Fair Funding Review 2.0, aim to shift more cash towards areas with higher deprivation.
From BBC ● Oct. 22, 2026
The immense pressure found in subduction zones can transform rocks into a distinctive red and green material known as "eclogite."
From Science Daily ● Oct. 22, 2026
The rocks became bigger, the trees smaller; then the trees were left behind entirely as they streamed out onto a stone flatness like nothing he’d ever known.
From "Wolf Brother" by Michelle Paver
So had the right leader been waiting in the wings, knowing what needed to be done the whole time?
From The Wall Street Journal ● Oct. 21, 2026
All that is to say, Hanawalt has grown more comfortable in not quite knowing what’s next.
From Los Angeles Times ● Oct. 21, 2026
He added that knowing island life really helped, especially as he said most shops on Anglesey shut at 19:00 and he would end up eating a Pot Noodle in the evenings.
From BBC ● Oct. 19, 2026
That said, doctors say that knowing the symptoms and getting treated early makes a big difference.
From MarketWatch ● Oct. 19, 2026
Folks are probably laughing, knowing I’m a farm kid trying for adventure.
From "Will’s Race for Home" by Jewell Parker Rhodes
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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.
