How should I choose between [知]{し}る and わかる?


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?




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.




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.

