Say Like a Local

How to Say "I Know" in Japanese

The usual way is 知っています (shitte imasu) in polite speech and 知ってる (shitteru) in casual conversation. Both are used for knowing a fact or piece of information.

The most common way

shitte imasu

I know — neutral and polite, used about facts or information you are aware of.

How to say it: The small っ doubles the t: pause briefly on the t in shi-tte-i-masu. Don't blur it into a single-t 'shiteimasu'.

Other ways to say it

  • casual

    shitteru

    I know — the everyday spoken contraction of 知っています, relaxed and natural.

    When to use it: With friends, family, or colleagues you're close to in ordinary conversation.

  • friendly

    shitteru yo

    I know! — adds a light, reassuring or slightly insistent tone so it doesn't sound curt.

    When to use it: When someone tells you something you already know and you want to sound warm rather than dismissive.

  • neutral, slightly impatient

    wakattemasu

    I know, I get it — signals you already understand something, and can hint at mild impatience.

    When to use it: When someone keeps reminding you of something you already understand; polite but a little defensive.

  • formal, business

    shōchi shite imasu

    I'm aware of it / noted — a formal acknowledgment of information.

    When to use it: At work when a boss or client gives you information and you want to sound professional.

  • very formal, humble

    zonjite orimasu

    I know (humble) — the humble form, often used about knowing a person's name or a fact.

    When to use it: Speaking to a superior or someone far above you socially, for example confirming you know their name.

In a conversation

  1. A

    、？

    Ashita no kaigi, ku-ji kara da yo ne?

    The meeting tomorrow is from 9, right?

  2. B

    、。

    Un, shitteru yo.

    Yeah, I know.

  3. A

    ？

    Shiryō wa mō junbi shita?

    Have you prepared the materials yet?

  4. B

    、。

    Mochiron, wakatteru tte.

    Of course — I've got it.

Common mistakes

  • 知ります → 知っています

    知る describes the moment of finding something out, so the plain present 知ります isn't used for 'I know' — the ている form is.

  • 分かります → 知っています

    分かる means 'understand', while 知る is the verb for having knowledge of a fact.

  • 知ってるです → 知っています

    知ってる is the plain form and can't be followed by です; use the polite 知っています instead.