Both 知る and わかる get used for "know", "understand", "learn", "find out", and various other concepts. How do you know which to use when? Are there any rules to help you decide?

Additionally, both of these verbs regularly appear in several different forms:

  • 知る、知った、知っている

  • わかる、わかった、わかっている

In what situations do you use each form, and how does the meaning change?

  • 1
    I think it'd be worth adding 理解する in there too, as it's not very clear when to use it vs. 分かる
    – Mark H
    Commented Jun 30, 2011 at 19:08
  • 2
    @Derek: any particular reason you rolled back my edit of the title? I can't really see why one word should be in kanji and not the other (afaik, they are both equally common), but maybe i'm missing something else...
    – Dave
    Commented Jul 2, 2011 at 16:27
  • 5
    @Dave: I intentionally left わかる as hiragana because I wanted to include the entire range of わかる rather than just one of the narrower, kanjified versions. Commented Jul 2, 2011 at 19:17

11 Answers 11


As stated in some of the other answers, the fundamental difference is that 分{わ}かる is "to understand", and 知{し}る is "to know", which helps differentiate the two as concepts. However, I think that doesn't fully answer your question.

Many years ago, early in my Japanese learning, when a Japanese friend asked me what I was going to do tomorrow, I said 「知{し}らない」, and my friend laughed. She explained that it would be more common to answer 「分{わ}からない」.

This would be opposite to English, where our answer would be that we "don't know" what we're going to do tomorrow, which is why I thought to say it that way. To say we "don't understand" what we're going to do tomorrow could be awkward enough to get a laugh.

After exploring the reasons why she laughed, I believe the difference comes down to a concept of 内{うち}, "inside", versus 外{そと}, "outside", which is a large and useful concept to grasp in Japanese culture and language. It's too big to go fully go into here, but a very short description is that in Japanese culture there is a high degree of sensitivity to how some people and information is part of the "inner circle" of your life, and other people and information are not included.

As it relates to 分{わ}かる and 知{し}る, you can think of it like 分{わ}かる has an implication of your personal knowledge, the things that relate to you, the things a person can decide on, etc... Only you can "know" what you do tomorrow, or decide on it, or reflect on it. It is 「内{うち}のこと」, so to speak. Thus, 分{わ}かる is the appropriate term for such matters.

Whereas 知{し}る is for the things that are facts independent of you, like the atomic weight of cesium, what the airspeed velocity of a sparrow is, how Korean and Japanese chopsticks differ, etc... 「外{そと}のこと」.

That said, it would be a mistake to draw a hard line to separate what is personal knowledge and what is a fact in the universe.

You could use 分{わ}かる for the airspeed velocity of a sparrow, if it was something you studied and knew about. By learning about it, you develop a relationship to the information, and it becomes 内{うち}のこと. If, for example, you were a professor of ornithology at Tokyo University and had done your dissertation on sparrow flight speeds.

In an opposite situation, you could use 知{し}らない for something that might ordinarily be thought of as 内{うち}のこと. For example, using 知{し}らない to say that you don't know what your father is doing tomorrow. However, by saying that what your father is doing is 外{そと}のこと, you are conveying that this is something external to you, which seems cold since you're talking about your dad. It says something about your relationship as well as your knowledge.

As a result, there can be an implication if "I don't care" interwoven into the use of 知{し}らない in some situations. My friend laughed at me saying 知{し}らない for what I am going to do tomorrow, because it's as if the next day's schedule is some kind of established fact that I have not cared enough to study. Even more extreme than not knowing what my father is going to do, I have a disconnect to my own life.

Even though it might be that what happens tomorrow is contingent on circumstances beyond my control, like my boss calling me in for work or an asteroid destroying my city. It's still up to me to react to what happens, to own the knowledge, and convey it to you. What will happen tomorrow is information that flows through me, so it is 内{うち}のこと.

Further, 内{うち}のこと isn't always your 内{うち}のこと, but it can be somebody's. In the news, they often report information using 分{わ}かる to convey that the information comes via someone else, and so responsibility for the information is not on the reporter. Similar to how in English we would use terms like "alleged", "revealed", "reported", and other terms that pass the buck. The news is often other people's 内{うち}のこと.

Of course when it comes right down to it, there will be a big, smudgy, greyish boundary between the two concepts. No doubt people could come up with a many borderline cases where one or the other might equally apply. I think it's the kind of thing that native speakers might disagree about which is more correct in certain specific circumstances.

Hope that helps.

  • 3
    This is an elegant explanation (I don't think I've ever heard it explained as a parallel of 内 and 外 before), but I'm wondering if the exceptions might outweigh everything else. There are many "facts independant [sic] of you" where わかる, not 知る, is used: メルトダウンの原因がわかった, (ある人が)これから何をするかはだれにもわからない, コピー機の使い方がよくわからない, and so on. These things are all independent of you: an established cause, another person's will, a set method. So while the 内/外 analogy sounds nice, I don't think it covers enough cases to be regarded as a general rule. Please correct me if I've missed your point. Commented Jul 1, 2011 at 14:38
  • 4
    I think the point I failed to convey, which led to your suspicions, is that the focus is not on the information, but on the speaker's (or somebody's) relationship to it. All the examples you cite are situations where there is a certain expectation of participation: someone at the plant reported the situation, the people around the guy doing inexplicable things could talk about it, you could read the copy machine manual. If you used 知る/知らない for any of those situations, which I believe would be grammatically correct, you place distance between the people involved and the information saught.
    – Questioner
    Commented Jul 2, 2011 at 4:32
  • 8
    Can I +1 this twice?
    – rintaun
    Commented Jul 3, 2011 at 9:29
  • OK, so to put this another way, are you using 内 and 外 to indicate the level of internalization? So a concept that has been internalized/understood to a deep level or with which you have a more-than-superficial relationship gets わかる, while a simple datum or concept from which you are emotionally separated gets 知る? Commented Jul 6, 2011 at 20:24
  • 4
    @Uberto: The idea that different parts of the brain are involved, like the patently false belief that Japanese have longer intestines that other people, is more than just highly suspect. But, I would be fascinated to see evidence that supports it, so if you can point to any, then please do.
    – Questioner
    Commented Jul 22, 2011 at 10:02


I believe the confusion comes from the fact that 知る is not "to know", but it is actually "to come/get to know." 「知る」is related to perception and sense. This is the broader concept of hear, read, see, learn, etc. which makes someone sure about it. And, 知っている means "have come/gotten to know", so it is quite close to "know."

On the other hand, 分かる describes one's ability to tell the difference.

They are sometimes interchangeable like 「この漢字、知ってる?」and「この漢字、分かる?」.

However, sometimes the meaning drastically changes, and it can be natural only in an unusual situation because 知る should be related to perception and sense and 分かる should be related to an ability.

I see many good answers here. The concept of "inside or outside" in another answer strikes close to a good point. But, I think that answer is a little bit confused because it fails to understand that "to know" is a stative verb but 「知る」is not. A stative verb is a verb which describes state of something. On the other hand,「知る」is a dynamic word, which describes changes.「知る」is "to get/come to know" not "to know." "to know" is 「知っている」. This also happens to "to have" and 「持つ」.

Let's check some examples.

私はその時にそれを知った。(I didn't know it just before that time, and I knew it just after that time.)

I knew it at that time. (私はその時それを知っていた。)

私はその時にそれを持った。(I didn't have it just before that time, and I had it just after that time.)

I had it at that time. (私はその時それを持っていた。)

So, first of all, there are huge differences between Japanese and English. And, these lead you to the idea of "inside or outside." 「知る」often happens when something comes in.

On the other hand,「分かる」is a stative potential verb. It basically describes someone's ability.

Sometimes, it is possible to use both「知る」and「分かる」. For example, "Do you know this Kanji?" can be translated to both「この漢字、知ってる?」and「この漢字、分かる?」 But sometimes it is not possible to use them interchangeably or the meaning changes.

「知る」is related to perception and sense. This is the broader concept of hear, read, see, learn, etc. which makes someone sure about it. So,「知ってる」means "「知る」has happened and the effect still continues."

「分かる」is related to classification and distinguish. If you have an idea, or if you can explain, link or conclude something, you「分かる」.

I guess the best way to know the difference is to make many examples and compare them!


Taro pointed Jiro, and asked Hanako "Do you know him?"

  1. 太郎は次郎を指さして「この人を知ってますか。」と花子に聞いた。
  2. 太郎は次郎を指さして「この人が分かりますか。」と花子に聞いた。

The sentence 2 can be natural if 太郎 suspects 花子 loses her memory or if 次郎 is in a panda costume or if 次郎 and 花子 have not seen for a long long time or if 次郎's face has changed. On the other hand, sentence 1 can be natural in more general cases. It basically means "Do you know this person?"

In this case,

  • 「知ってますか。」=> Have you seen him?
  • 「分かりますか。」=> Can you recognise him?


Suppose that there was a cake on a table, but it disappeared at night.

  1. 「夜、誰か知らない人に食べられていたよ。」
    • "I saw a stranger come in at night and eat the cake."
  2. 「夜、誰か分からない人に食べられていたよ。」
    • "I saw someone eating the cake at night, but I did not find out who it was."

In this case,

  • 「知らない」=> Someone I haven't seen.
  • 「分からない」=> Someone I could not recognise.


Do you know what you are going to do tomorrow? No.

  1. 「明日の予定は?」「知りません。」
  2. 「明日の予定は?」「分かりません。」

Actually, the sentence 1 can be natural, for example, if you are a prisoner. You are not going to decide what you are going to do tomorrow, but someone will order you to do something. You can use the sentence 2 in either case.

In this case,

  • 「知りません。」=> I haven't been told.
  • 「分かりません。」=> I have no idea.


"I felt that I knew that face, and now I know who he is."

  1. 「あの顔、知っていると思っていたけれど、ようやく誰か分かった。」
    • "I felt I'd seen that face, and now I identified him."
  2. 「あの顔、分かっていると思っていたけれど、ようやく誰か知った。」
    • This sounds a little bit strange because it is natural only in a strange case. For example, "Alice was in disguise. I thought it was Bob. But now you tell me that it was Alice. And, now I know that it was Alice."


「あれ、Alice と Bob ってどういう間柄か知ってるよね?」"Wait, do you know the relationship between Alice and Bob?"

「知らない。」"No, I do not know."

「Bob のお母さんが Catharine っていうの知ってる?」"Do you know that Bob's mother is Catharine?"

「知ってる。」"I know."

「Catharine と Alice は双子の姉妹なんだよ。」"Catharine and Alice are twins."

「へえ、はじめて知った。」"Huh, this is the first time I know of that."

「よく見ると、顔がそっくりでしょう?」"They look so alike if you look them carefully."

「たしかにそう思っていたけれども、姉妹だとは分からなかったなあ。」"Yeah, I've noticed that, but I did not know that they are sisters."

「Alice と Bob ってどういう間柄か、分かった?」"Do you know the relationship between Alice and Bob?"

「うん、分かった。ありがとう。」"Now I know. Thanks."

次の日。next day.

「Alice は Bob のおばさんだって、昨日知ったよ。」"Yesterday I knew that Alice is Bob's aunt."


  1. 「あの電車の今のスピードは?」


  1. 「あの電車の今のスピードは?」

「だいたいなら分かるよ。電柱の間隔が 100 m おきだから、この時計を参考にすると、時速90キロくらいだね。」

In this case,

  • 「知ってる。」=> I've heard of it from the authority.
  • 「分かる。」=> I can calculate it.


  1. メルトダウンの原因をしった。
    • If someone told me the reason.
    • If I went close to the atomic furnace and found an alien ship!
  2. メルトダウンの原因がわかった。
    • If we studied the reason for the meltdown and now we are sure.

In this case,

  • 「知った。」=> I heard of it. / I saw the CAUSE!
  • 「分かった。」=> Now I got the reason.


  1. (ある人が)これから何をするかはだれも分からない。
    • No one can guess.
  2. (ある人が)これから何をするかはだれも知らない。
    • No one is told.

In this case,

  • 「知らない。」=> Have not heard.
  • 「分からない。」=> Have no idea.

By the way, you can say "誰にも分からない" but not "誰にも知らない." But, you can say "誰にも知られていない."


  1. コピー機の使い方がよくわからない。
  2. コピー機の使い方をよくしらない。

These two are almost the same.

In this case,

  • 「知らない。」=> Have not learned.
  • 「分からない。」=> Cannot use.


  1. 「それ食べちゃ駄目だよ。」「分かったよ。」
    • "You should not eat it." "I see."
  2. 「それ食べちゃ駄目だよ。」「今知ったよ。」
    • "You should not eat it." "Now I understand that."

I feel slight accusation from the second one because it sounds like "This is the very first time you tell me that." or "Why didn't you told me earlier?" Also,「今分かったよ」and「知ったよ。」are not natural responses.

  • 「分かった。」=> I changed my state to "understood."
  • 「知った。」=> A certain fact comes into me.


  1. 私は自分の前世が分かる。
  2. 私は自分の前世を知っている。
  • 「分かる」 => I remember my past life / I have an ability to describe my past life.
  • 「知っている」 => I've been told, and I am sure.

「知る」 is used when you actively learn or learn about something, whereas 「わかる」 is more for things that have been brought to your awareness regardless of involvement.

Consequently, 「わからない」 is used when you are not aware of/don't know something, whereas 「知らない」 is used when you are willfully ignorant of something. Therefore 「知らない」/「知りません」 should be avoided since it denotes that you are/were not willing to find out about the fact in question.

  • 2
    I understand that there are times when 知らない can imply "I don't know [and I don't care to know]", but this is not always the case. For example, you might not have sufficient data on hand to make a statement, so you could easily say 手元に資料がないので、そこまでは知りませんが… without sounding "willfully ignorant" at all. Commented Jul 1, 2011 at 14:46
  • You're making the assumption that willful ignorance is always a negative thing, which is not true. There are cases where it is just a simple fact, such as with 「知らない人」; once can't know all 7 billion or so people on this planet... Commented Jul 1, 2011 at 14:52
  • 4
    Perhaps I don't understand what you mean by "willful ignorance" then. In my mind, willful ignorance means that you have means and opportunity to know something, but you actively choose not to. Not knowing a fact for which you have never been presented the opportunity to know cannot involve the will, so it cannot be willful ignorance. Perhaps "active ignorance" and "passive ignorance" are better terms? But if 知らない can be used for both active and passive ignorance, you cannot make the general statement that 知らない should be avoided, since as you pointed out, passive ignorance is not negative. Commented Jul 1, 2011 at 15:05

Other people have talked about the difference between 知る and 分かる so I won't touch that one (especially since people far more knowledgeable than myself have already answered), but I did want to make one point about the different forms, since I haven't seen that addressed yet.

I was watching a TV show in Japanese once when a this girl and guy each had crushes on each other so they flirted alot, but the guy always did things to make the girl angry. One time she got annoyed but she tried to hide it, but the other guy could tell. He asked her "haha what are you getting angry about?" and she responded, simply, 分かる?

It was then that the light bulb went off in my head. 分かる means "can tell". It also means "understand", but it depends on whether it's in a sentence or a question. I think the entire list is something like this:

分かった - Got it.

分かったか。 - Got it?

分かります。 - I can tell.

分かりますか。 - Do you understand? / Can you tell?

分かっている。 - I got it, I got it.

Obviously you aren't going to translate these phrases like this every time, but the meaning holds I believe. The important point about the っている form is that it seems to emphasize that this is not new information, which is why I repeated the phrase "I got it" twice.

As for the dictionary / ます form, I've never found a situation where "can tell" does not translate exactly from English into Japanese 分かります.

I can't tell what the weather will be like tomorrow.

Nobody can tell what the future holds.

(Looking far away / squinting) Can you tell if that lady is hot?

etc. The same distinction seems to apply to 知る and 知っている as well.

Note that this analysis is not backed up by any kind of reference, it's just a realization I came to on my own, so there may be some minor flaws in it.


Where did he go?

  • 分からない: no idea
  • 知らない: do I look like I know where he went? Go ask someone else, dude!

Oh, since we're talking about Japanese,

  • 日本語が分かりますか: do you understand Japanese?
  • 日本語は知っていますか: have you ever heard of this language called Japanese?

Don't f*ck with me

  • 桜庭を知っているよ! I know the best Pride FC fighter!
  • もうあんたの目的は分かっている! I clearly see what you want to do!


  • これ、初めて知った! Really? I had never though it would be the case!
  • やっと、分かった! At last, I understand what you meant!

To sum up: if you don't get the logic, choose what a good speaker would say! (Yes, it sounds stupid and obvious, but that's how it works when languages are very different from yours)

  • 3
    "…if you don't get the logic, choose what a good speaker would say!" What logic have you put forth? You have given me a list of examples, which I could easily find on Google or from a podcast. My goal with this question is to discover the logic behind this pair, and an answer that essentially says, "Just listen to what other people use and imitate that," helps me not in the least. Commented Jul 1, 2011 at 14:52
  • 2
    @Derek: I did not claim I gave any logic. What I did claim, is that to understand the difference, you have to study usage. I tried to give examples that were systematic. With only those, you should be able to get 80% or more of your usages correct. If you were looking for a linguistics answer, I'm sorry; I just care about being able to produce sentences that a native speaker would produce, without thinking.
    – Axioplase
    Commented Jul 3, 2011 at 3:44

To understand the difference, you need to know where 分かる comes from. Pun intended. わかる is the intransitive form of 分ける, meaning "to separate". If I 分ける something, I divide it out, but if I わかる something, the dividing would be done in me. Another way of translating it would be "parsing out an idea from all the rest". In the case of the scenario about knowing what you would do tomorrow, you would say 分からない, meaning "I haven't parsed/figured that out [yet]."

わかっている would thus mean "parsing". You might use this if someone is trying to drill something into your head when you already heard them the first time. わかっているよ!! ("I'm parsing it out already!")

知る is literally "to know", but that specifically means "to possess [what we might call static] information" as opposed to making decisions. 知っている would be "knowing".

I could be wrong about all this, but it's pretty consistent with my experience.

  • 1
    I follow your logic but when you say "parsing" do you mean "have already parsed"? 分かっている is normally static ("subject change") but translating it as "I'm parsing it out already!" does not sound very natural in English and for anybody trying to grasp ~ている is quite confusing.
    – Tim
    Commented Apr 6, 2014 at 8:57

When I was in college one of my professors taught us a basic principle for telling when to use each:

分からない: I don't know (generic, but with a sense that it's pertinent to the speaker)

知らない: I don't know, and I have no reason to (not relevant to the speaker)


You can't 'understand' (わかる) a person, place or thing. You can't 'know' (知る) a concept.

That's a bit of a generalization, but will get you through most of it. Learning by context is very important, though, so you should be getting a lot of input to help resolve questions like this.

  • 1
    I think there is quite a bit more to this than simply what you can't do with each of them.
    – rintaun
    Commented Jun 30, 2011 at 18:43
  • +1 yes, it's simply the difference between 'to understand' and 'to know'. Going further in the explanation is like explaining what is the difference between the English terms...
    – repecmps
    Commented Jul 1, 2011 at 1:03
  • 3
    I 'understand' (分かる) Japanese, which is a thing, as I speak it. And I know (知る) it too, since it is a famous language.
    – Axioplase
    Commented Jul 1, 2011 at 2:10
  • I don't think the terms are 1-to-1 between Japanese and English (or even that close)... In fact, I think this translation shortcut is the source of many errors (quite like the 行く/来る = go/come oversimplification). See @DaveMG's answer below for a good example...
    – Dave
    Commented Jul 1, 2011 at 2:57
  • 1
    No, 分かる does not simply mean to understand and that's all there is to it. If someone asks you what time it is, do you reply, "I don't understand?" if you do not have the time? That means you don't understand the question.
    – Kaz
    Commented Oct 20, 2013 at 3:55

知る is basically used for the new knowledge or idea or thoughts...something new. When you 知る something, it means that you didn't know it before. So, 知った implies that you just heard or seen something new for you, not necessarily means that you understood it.

Whereas 分かる is not used only for the new things but also something you've already heard or seen. When you 分かる something, whether it's new for you or not, you understand it or at least try to do. When you comfort your friend who got heart-broken, for example, you would say "その気持ち分かるよ (I know/understand how it feels like)" even you didn't have the same experience. 分かった expresses that you understand/understood it.

知っている and 分かっている are exchangeable in many contexts, however, 知っている is more about the knowledge.

Answering to the question like "明日は何をしますか?" or "先生はどこにいますか?", 分かりません/分からない is preferred because it impresses to the listener that the speaker made an effort to asnwer. You could use 知りません/知らない but it sounds a bit cold.

It depends on the context but 知る and 分かる are used like below:

知らなかった = I didn't know (hadn't heard/seen it before).

分からなかった = I didn't know/understand it (although I tried).

知っていたけど分かっていなかった = I knew it (and I thought I understood) but didn't understand.


I would like to approach this question from a purely grammatical aspect.

知る is a transitive verb.

分かる is historically the intransitive verb of 分ける. Just like most intransitive verbs, it can function like an potential verb or passive verb.

The main reason you use a intransitive or potential verb is to express:

  1. the result of some activity you want to accomplish

    You want to achieve some kind of result, so you check what happens now and then


    When you have been looking for the answer, わかる is chosen because it's just the result you want. 偶然知った⇔やっとわかった

  2. the difficulty of some activity or low probability of some event

    Just like 1, if you know something is difficult because someone wants to make it happen but fails. It must be something important or desirable, otherwise people won't try to do it.


    Using intransitive verbs sounds more awesome. It implies not everyone can.

The main reason you use a intransitive verb or passive verb is to express:

  1. the event without mentioning the actor or there is no actor at all.

    家に死体を見つけた(私は implied)→家に死体が見つかった(誰かに implied)
    原因を明らかにした(私は implied)→原因が明らかになった(誰かに implied)

    分かった in this case is basically the same as 判明した.

I think it more or less explains the 内/外 difference.

Sometimes, わかった is used immediately after you happen to know/realize something, e.g. それを見て何かわかった. But in Classical Japanese, 知りぬ(知ってしまった) is used. (われ朝ごと夕ごとに見る竹の中におはするにて知りぬ) Many verbs about perception tend to be intransitive. e.g. 気づく, 見える, 聞こえる, etc, both some else do not: 感じる, etc. I haven't found a good explanation.

In modern Japanese, it seems that there is not a exact transitive counterpart of 分かる. When わかる means “to understand”, 理解する can used. But 理解する is a little literary and not used for trivial things. So you may often see ~を分かってほしい. 了解した can be used instead of わかった as a response.

On the other hand 知る is irregular, too. You say 知っている but 知らない. 知れる is almost only used in fixed expressions. わかる is often used instead of 知れる when you want to.


My summary:


  • Core meaning: to become aware of; to find out (a fact)
  • Shades closer to French savoir, German wissen etc.
  • Kanji gloss: wisdom (i.e., knowledge that you gain either through study or observation)
  • Commonly used in te-iru form, analogous to 死ぬ
  • Grammatical subject is the person
  • Topic is normally the subject
  • Used for observations about the outside world, etc.


  • Core meaning: to be comprehensible
  • Shades closer to French connaître, German kennen etc. (in sense, not grammatically)
  • Kanji gloss: parse (i.e., split into more manageable pieces)
  • Self-move (自動詞) form of 分ける (the latter is not used in this sense, but it can mean "to distinguish between")
  • Grammatical subject is the comprehensible thing
  • Topic is normally the comprehending person
  • Used for things about oneself, which are not "observed" in the same way

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