LESSON NOTES · レッスンノート

N4How you sound · Sep 22, 2026

わからない vs 知しらない: two ways to say "I don''t know", one of them cold

分わからない means the answer is not something you can work out; 知しらない means the information was never in your head — and because 知しらない can imply "and it is not my business," 分わかりません is the safer "I don't know" with strangers and at work.

Both translate as "I don't know," and choosing wrong rarely confuses anyone — it just makes you sound colder than you meant. The grammar around them is also lopsided in a way that catches every learner: the positive of 知しる is 知しっています, but the negative is 知しりません, never 知しっていません.

The basics

What is the actual difference?

分わかる is about comprehension: something becomes clear to you. 知しる is about acquisition: a piece of information enters your head.

道みちが分わかりません。 — I can't work out the way. (polite, you are looking at a map and failing) その店みせは知しりません。 — I don't know that shop. (polite, you have never heard of it)

So 分わからない is a failure to understand or determine, and 知しらない is an absence of information. A person can 知しっている the word and still 分わからない what the sentence means.

漢字かんじは知しっていますが、意味いみが分わかりません。 — I know the kanji, but I don't understand the meaning. (polite, the distinction in one sentence)

Which one is safer to say?

分わかりません, almost always. 知しりません is grammatically fine and tonally risky: because it states that the information is simply not yours, it can read as "I have nothing to do with this."

すみません、分わかりません。 — Sorry, I don't know. (polite, safe with anyone) 知しりません。 — I don't know / not my business. (polite form, but can land cold)

Shop staff and receptionists almost never say 知しりません to a customer for this reason. They say 分わかりかねます ("I am unable to determine") or 確認かくにんいたします ("I'll check"). If you are ever unsure which to use, 分わかりません cannot offend anyone.

Why is it 知しっています but 知しりません?

Because 知しる marks the moment information arrives. Once it has arrived, you are in the resulting state, which is why the positive needs 〜ている. The negative is the plain form, because you never entered the state at all.

知しっています。 — I know. (polite, the state of having learned it) 知しりません。 — I don't know. (polite, you never learned it)

知しっていません is the single most common error with this verb. It is not a subtle mistake — it sounds broken to a native ear. The 〜ている form is doing something specific here, and why 知しっている means "I know" works through the same logic for other verbs.

What particle does 分わかる take?

が, not を. 分わかる is not "to understand [something]" so much as "[something] becomes clear" — so the thing you understand is the subject.

日本語にほんごが分わかります。 — I understand Japanese. (polite) 意味いみがよく分わかりません。 — I don't really understand the meaning. (polite)

日本語にほんごを分わかります is wrong, and it is a mistake learners make for months because English has a transitive verb there. The が here is doing the job described in は vs が — marking what the sentence is about, not what you are acting on.

Beyond the basics

Which one in which situation?

Situation Say Why
A stranger asks for directions you can't work out 分わかりません Safe, warm, about your ability
Asked about a shop you have never heard of 知しりません / 分わかりません Either; 分わかりません is softer
Your boss asks about a file you never saw 分わかりかねます / 確認かくにんします 知しりません sounds dismissive upward
A teacher asks you a question in class 分わかりません You cannot work out the answer
Asked whether a celebrity is famous in your country 知しりません Pure information
Understanding an instruction 分わかりました Acceptance, not knowledge
You genuinely have no involvement 知しりません The cold reading is the correct one

Why is 分わかりました past tense?

Because understanding arrived at a point in time. Japanese marks the arrival; English marks the resulting state. 分わかりました is the standard "understood, got it," said the instant the point lands.

分わかりました。 — Understood. (polite, accepting an instruction) 分わかります。 — I understand / I can see that. (polite, ongoing sympathy or comprehension)

分わかります in answer to an instruction sounds odd — like saying "I am capable of understanding" rather than "got it." Use 分わかりました for tasks and 分わかります for sympathy: お気持きもちは分わかります, "I understand how you feel."

What are the polite and humble versions?

知しる has a full set, which you will hear constantly in shops and offices.

ご存ぞんじですか。 — Do you know? (honorific, about the other person) 存ぞんじません。 — I do not know. (humble, about yourself) 分わかりかねます。 — I am unable to determine that. (formal, service register)

分わかりかねます is the phrase to recognise: 〜かねる means "cannot bring oneself to," so it declines without ever saying no. Staff use it precisely because it avoids the coldness of 知しりません. Choosing among these rungs is the everyday work described in keigo vs casual.

How casual can they get?

Both shorten, and the shortened forms carry attitude.

わかんない。 — Dunno. (casual, extremely common in speech) 知しらない。 — Don't know. (casual) 知しらん。 — Dunno / don't care. (casual, blunt; standard in Kansai speech) 知しらんけど。 — …but what do I know. (Kansai, tacked on after an opinion to disclaim it)

知しらんけど deserves its own note: it is a Kansai habit that spread nationally, used to end a confident statement with a shrug. It is a joke about responsibility, not real doubt, and it belongs to the dialect landscape in Japanese dialects.

What about the anime versions?

Fiction leans hard on the cold reading, which is exactly why it is worth flagging.

知しるか! — How should I know! / I don't care! (rude, dismissive) 知しらねぇよ。 — Dunno, don't care. (rough masculine) 分わかってない。 — You don't get it. (casual, often accusatory) 分わかってる。 — I know, I get it. (casual; can be impatient depending on tone)

知しるか is not a stronger "I don't know" — it is a refusal to engage, closer to "not my problem." Learners who pick it up from anime and use it in a real conversation cause exactly the reaction you would expect.

Common mistakes

  • 知しっていません. Does not exist. The negative is 知しりません or 知しらない.
  • 日本語にほんごを分わかります. 分わかる takes が: 日本語にほんごが分わかります.
  • 知しりません to a customer or a superior. Grammatically polite, tonally dismissive. Use 分わかりません, 分わかりかねます, or 確認かくにんします.
  • 分わかります as "got it." For accepting an instruction, use the past: 分わかりました.
  • Using 知しるか because it appeared in anime. It means "how should I know," with the force of a slammed door.
  • Treating them as interchangeable in self-description. 日本語にほんごが分わかりません means you cannot follow the language; 日本語にほんごを知しりません would suggest you have never heard that such a language exists.

Practice

Answers are hidden — build yours first, then open. Questions 1 and 2 are a pair: the same three words, one positive and one negative.

1. Say "I know that shop" politely.

Show answer

その店みせは知しっています — the positive takes 〜ている because knowing is the state that follows learning.

2. Now say "I don't know that shop" politely.

Show answer

その店みせは知しりません — the negative is the plain form. 知しっていません is the pair's trap and does not exist.

3. A stranger asks for directions to a building you cannot locate on your map.

Show answer

すみません、分わかりません — this is about your ability to work it out, and it is the warm option. 知しりません would sound like brushing them off.

4. Fix this sentence: 日本語にほんごを分わかります。

Show answer

日本語にほんごが分わかります — 分わかる takes が, because the thing understood is the subject, not the object.

5. Your manager explains a new procedure. Accept it.

Show answer

分わかりました — past tense, because the understanding arrived just now. 分わかります here would sound like "I am able to understand."

6. Say "I understand how you feel."

Show answer

お気持きもちは分わかります — ongoing comprehension, so present tense. This is the one place 分わかります beats 分わかりました.

7. You work at a front desk and a customer asks something you cannot answer.

Show answer

分わかりかねます / 確認かくにんいたします — service register. 知しりません to a customer is the classic tonal accident.

8. Ask a client politely whether they know about a service.

Show answer

ご存ぞんじですか — the honorific form of 知しる, used about the other person. About yourself it would be 存ぞんじません.

9. Say "dunno" to a close friend.

Show answer

わかんない — the reduced casual form. 知しらない also works but leans towards "no information" rather than "can't work it out."

10. A character shouts 知しるか! — what did they mean?

Show answer

"How should I know / not my problem" — it is a refusal to engage, not a stronger "I don't know." Recognise it; do not say it.

FAQ

Is 知しりません actually rude? Not rude, but flat. It states an absence of information with no softening, which in a service or workplace context can read as indifference. Adding すみません in front softens it a great deal.

Can I always just use 分わかりません? Nearly always, and that is a reasonable strategy while you build the feel for it. The only odd case is pure information about the world — "is this singer famous in your country?" — where 知しりません is the accurate answer.

Why does 分わかる mean both "understand" and "know"? Because it covers anything that becomes clear, including facts you work out. 名前なまえが分わかりました means "I found out the name" — the information became clear, rather than being taught to you.

What is 分わかりかねます exactly? 分わかる plus 〜かねる, "cannot bring oneself to." It is formal service Japanese for "I am not in a position to say," and it is far softer than a flat negative.

Is 知しらんけど rude? No — it is playful. It is a Kansai tag that disclaims responsibility for what you just said, and it has spread nationally as a joke. It does not belong in formal speech.

How do I say "I forgot" rather than "I don't know"? 忘わすれました. Learners often use 分わかりません when they mean they knew and lost it, and the distinction matters in a lesson — 忘わすれました tells your teacher to prompt you instead of re-teaching.

Vocabulary from this article

Tap the block to select all of it, then copy. In Anki: File → Import, note type Basic, separator Tab — the first column becomes the front, the second the back.

分かる	わかる — to understand, to become clear
分かりません	わかりません — I don't understand, I can't work it out
分かりました	わかりました — understood, got it
分かります	わかります — I understand (ongoing)
分かりかねます	わかりかねます — I am unable to determine (formal)
わかんない	わかんない — dunno (casual)
知る	しる — to come to know
知っています	しっています — I know
知りません	しりません — I don't know (no information)
知らない	しらない — don't know (casual)
知らん	しらん — dunno, don't care (blunt, Kansai)
知らんけど	しらんけど — …but what do I know (Kansai tag)
ご存じ	ごぞんじ — knowing (honorific, about others)
存じません	ぞんじません — I do not know (humble)
確認する	かくにんする — to check, to confirm
意味	いみ — meaning
気持ち	きもち — feeling
忘れる	わすれる — to forget

I'm Yuuki, a Japanese teacher based in Tokyo. I've taught on italki as a Top 1% teacher and watched over 1,500 anime. 知しっていません is the mistake I hear in nearly every beginner's first month, and the fix is not a rule to memorise — it is noticing that Japanese treats knowing as a state you entered, so the negative is simply never having entered it.

Book a trial lesson · $13

Sources: the author's own lessons and standard reference grammars.

More drills like the ones above, plus a timed JLPT-style mock test: Practice · N4

Want to try this in a real conversation?

30-minute trial lesson, $13. Times shown in your own timezone.

Book a trial lesson · $13