Irregular verb
The verb to know
know → knew → known
A1Meaning: to have information in your mind; to be familiar with someone · Type: irregular · Frequency: Top 10 English verbs
Key points to remember
- Present Simple:
I/you/we/they know·he/she/it knows - Past Simple:
knew(said /njuː/) - Past participle:
known - -ing form:
knowing
Conjugation of the verb to know
Present Simple
| I | know |
| You | know |
| He / She / It | knows |
| We | know |
| You (pl.) | know |
| They | know |
Present Perfect
| I | have known | I've known |
| You | have known | You've known |
| He / She / It | has known | He's / She's / It's known |
| We | have known | We've known |
| You (pl.) | have known | You've known |
| They | have known | They've known |
All the forms of the verb to know
Present Simple
Full pageknow / knows
“I know the answer.”
See the pagePresent Continuous
Full pageam / is / are knowing
“I know the answer (not I am knowing the answer).”
See the pagePast Simple
Full pageknew
“I knew the answer immediately.”
See the pagePast Continuous
Full pagewas / were knowing
“I knew the answer (not I was knowing the answer).”
See the pagePresent Perfect
Full pagehave / has known
“I have known him for 10 years.”
See the pagePast Perfect
Full pagehad known
“I had never known the answer before that day.”
See the pageFuture Simple
Full pagewill know
“I will know the answer tomorrow.”
See the pageGoing to Future
Full pageam / is / are going to know
“I'm going to know the answer this weekend.”
See the pageConditional (would)
Full pagewould know
“I would know the answer if I read the book.”
See the pageHow to use to know
1. Knowing a fact or an answer
- I know the answer.
- Do you know the time?
- I knew he would come.
2. Knowing a person or a place
Here know means you have met the person, or you have been to the place.
- I know your sister.
- Do you know London?
3. Knowing someone for a long time (Present Perfect)
To say how long you have known someone, use the Present Perfect with for or since.
- I've known him for 10 years.
- We've known each other since high school.
4. Common expressions
You know is a small phrase people use a lot when they speak. As far as I know means you think it is true, but you are not completely sure. Who knows? means nobody can be sure.
- you know
- as far as I know
- who knows?
- I don't know
Common mistakes to avoid
1. We know new words in class ❌
Know is a state. Learn is an action. In class, you learn new words: We learn new words in class. After that, you know them: Now I know these words. Compare I know English (I can speak it) and I'm learning English (I am studying it now).
2. I knew him at a party last year ❌
For the first time you see someone, use meet: I met him at a party last year. Know is for the time after that: I met him in 2020, and I have known him since then.
3. Saying the k in know ❌
All verbs that start with kn- have a silent k. Say know, knew, known like this: /nəʊ/, /njuː/, /nəʊn/. It is the same for knee, knife, knight and knock.
Going further
Conjugating to know is a key skill in the English contest
Every year, the Big Challenge tests the key English verbs. Register your students so they can check their level in a real contest.
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Practise on PLAYYou can conjugate to know. Now say it out loud.
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Frequently asked questions
What is the past simple of know?+
The Past Simple of know is knew (said /njuː/). It is the same for every person: I knew, she knew, they knew. The past participle is known. Know → knew → known.
What is the difference between know and learn?+
Know is a state: the information is already in your head. I know the answer. Learn is an action: you are getting new information. I'm learning English. First you learn, then you know: I learned the poem last week, and now I know it by heart.
Why is the k silent in know?+
In English words that start with kn-, the k is silent: know, knee, knife, knight, knock. A long time ago, in Old English, people said the k. The pronunciation changed, but the spelling stayed the same.
How do you say how long you have known someone?+
Use the Present Perfect: I have known him for a long time, or I've known him for years. Use have known + for + a length of time. For a starting point, use since: I've known him since 2015.
What is the difference between know and meet?+
Meet is the moment when you see someone for the first time, or when you see a person you already know. Know is a state that lasts. I met him last year, and I've known him since then. When you meet someone new, say Nice to meet you. When you see a friend again, say Nice to see you.
Updated on 12 November 2026 by the Big Challenge teaching team. Every year, more than 500,000 students across Europe take part in our English contest, created in 1999. Our teaching approach →
The Big Challenge · Updated on 12 November 2026 · Source: www.thebigchallenge.com/bl/academy/learn-english/verbs/know
© The Big Challenge. Copying allowed for classroom use. Every year, more than 500,000 students across Europe take part in our English contest, created in 1999.