すみません。（私は）日本語が分かりません。
(Sumimasen. (Watashi wa) nihongo ga wakarimasen.)
Sorry. I don’t understand/don’t know Japanese.
The Many Ways to Say “I Don’t Know” in Japanese
“I don’t know” is one of the first things you should learn when studying a foreign language because it will surely come in handy!
In this article, I will introduce many ways to say “I don’t know” in Japanese, ranging from basic to idiomatic expressions. Let’s get started!
Casual Ways to Say “I Don’t Know” in Japanese
Let’s first start off by looking at the casual expressions to use when you don’t know something. These are the expressions you’ll hear native speakers use in everyday conversations with their friends, family, or coworkers they have a close relationship with.
1. 分からない (Wakaranai): I Don’t Know, I Don’t Understand
分かる (wakaru) means “to understand” in Japanese. When you want to say “I don’t know/understand,” you can change this verb into the negative form, 分からない (wakaranai).
You can say 分からない (wakaranai) to people who you have a close relationship with. However, it is better to use the polite form, 分かりません (wakarimasen), when speaking to strangers or people with a higher social status than you (boss, teachers, etc.).
You could also add です to the end of 分からない to make it more polite as well. 分からないです (wakaranai desu) is still polite, but sounds more friendly and casual than 分かりませんん.
Wakaranai is written in both kanji and hiragana:
- Kanji: 分からない
- Hiragana: わからない
Examples: Casual Version: 分からない (Wakaranai)
1. A child is doing his homework and talking to his mother:
お母さん、この問題の答えが分からないよ。
(Okāsan, kono mondai no kotae ga wakaranai yo.)
Mom, I don’t know the answer to this question.
2. At a supermarket:
子供: お母さん、このお菓子いくら？
Kodomo: (Okāsan, kono okashi ikura?)
Child: Mom, how much is this snack?
お母さん: 分からない。
Okāsan: (Wakaranai.)
Mother: I don’t know.
Example: Polite Version: 分かりません (Wakarimasen)
1. A student is talking to their teacher:
先生、この問題の答えが分かりません。
(Sensei, kono mondai no kotae ga wakarimasen.)
Teacher, I don’t know the answer to this question.
2. At a supermarket:
道子: すみません。ワインが欲しいのですが、在庫はありますか？
Michiko: (Sumimasen. Wain ga hoshii no desu ga zaiko wa arimasu ka?)
Michiko: I would like to buy a bottle of wine. Do you have any in stock?
店員: 申し訳ございません、ちょっと分からないので調べて来ます。
Ten-in: (Mōshiwake gozaimasen, chotto wakaranai no de shirabete kimasu.)
Store employee: I’m very sorry, but I am not too sure if we have it in stock. I’ll go and check right now.
3. At a train station:
乗客A: すみません。この電車は横浜に行きますか？
Jōkyaku A: (Sumimasen. Kono densha wa Yokohama ni ikimasu ka?)
Passenger A: Excuse me. Does this train go to Yokohama?
乗客B: ちょっと分かりません。あそこにいる駅員に聞いてみてください。
Jōkyaku B: (Chotto wakarimasen. Asoko ni iru ekiin ni kiite mite kudasai.)
Passenger B: I’m not too sure. Please ask the stration staff over there.
1. 分かんない (Wakan Nai): I Don’t Know, I Dunno
This is an even more casual version of 分からない (wakaranai). Because it is very informal, you should only use 分かんない (wakan nai) with people you are close to, like your family and friends.
In casual conversations, native Japanese speakers often change 分からない (wakaranai) to 分かんない (wakan nai) because it is easier to pronounce.
Examples:
1. 智子: 明日は晴れるかな？
Tomoko: (Ashita wa hareru kana?)
Tomoko: I wonder if the weather will clear up tomorrow?
花子: 分かんない。
Hanako: (Wakan nai.)
Hanako: I don’t know.
2. 健: あそこにいる人誰かな？
Ken: (Asoko ni iru hito dare kana?)
Ken: Do you know the person over there?
智子: 分かんない。
Tomoko: (Wakan nai.)
Tomoko: I don’t know.
2. 分からん (Wakaran): I Don’t Know, I Dunno
It seems that 分からん (wakaran) is mainly used in the Kansai (western) area of Japan. The meaning and usage of 分からん (wakaran) are the same as 分かんない (wakan nai). However, it can sound rough to people not from the Kansai area of Japan.
Examples:
1. 智子: 一樹は来るかな？
Tomoko: (Kazuki wa kuru kana?)
Tomoko: I wonder if Kazuki will come?
花子: 分からん。
Hanako: (Wakaran.)
Hanako: I don’t know.
2. 健: マイクはどこに行ったか分かる？
Ken: (Maiku wa doko ni itta ka wakaru?)
Ken: Do you know where Mike went?
智子: 分からん。
Tomoko: (Wakaran.)
Tomoko: I don’t know.
3. 訳わかんない (Wake Wakan Nai): I Don’t Know What you Mean
訳わかんない (wake wakan nai) means “I don’t understand the reasoning.” In more natural terms, “I don’t understand what you’re talking about” or “I don’t get it.”
The 訳 (wake) character in this expression means “a reason” or a “conclusion based on reasoning.” Put this together with the casual わかんない (wakan nai), and you get “I don’t understand this reasoning/conclusion.”
This phrase should only be used with your friends, family, or people you are very close to. Just like with all expressions, the way you say it is just as, if not more important than, the actual words. If you say this expression sharply or in a frustrating way, it can sound quite harsh or even demeaning. This expression should NEVER be used with your boss or someone in a higher position.
This expression is often used to express frustration.
Example:
先生が私にだけ沢山宿題を出したんだよ！もう訳わかんない！
(Sensei ga watashi ni dake takusan shukudai o dashitan da yo! Mō wake wakan nai!)
The teacher gave me a lot of homework, only me! I can’t understand why he did that to me.
4. 意味分かんない (Imi Wakan Nai): I Don’t Know What you Mean
意味わかんない (imi wakan nai) means, “I don’t understand the meaning” or “I don’t understand what you mean.” It is very similar to 訳わかんない (wake wakan nai) explained above.
Since these expressions have a similar meaning, they can be used interchangeably in most situations.
Example:
テレビを見ていたら、急にお父さんが怒り出して、宿題をやれって言ったんだよ！もう意味分かんない！
(Terebi o miteitara kyū ni otōsan ga okoridashite shukudai o yarette ittan da yo! Mō imi wakan nai!)
When I was watching TV, suddenly my father got angry and told me to do my homework! I don’t understand him!
5. 意味不明 (Imi Fumei): Incomprehensible, Meaning is Not Clear
This expression means, “It doesn’t make sense.”Teens often make it shorter and say 意味不 (imifu). We often see this expression on the internet written in katakana like this: イミフ (imifu).
Examples:
1. 健はいつも明子と喧嘩しているのに、それでもまだ一緒にいるなんて意味不明。
(Ken wa itsumo Akiko to kenka shiteirunoni, soredemo mada isshoni iru nante imi fumei.)
Ken and Akiko are always arguing, but they are still together. It doesn’t make sense.
2. 智子はダイエットしていると言いながらハンバーガーを食べて、コーラを飲んでいるよ。意味不明だね。
(Tomoko wa daietto shiteiru to iinagara hanbāgā o tabete kōra o nondeiru yo. Imi fumei da ne.)
Tomoko says that she is on a diet, but she’s eating a hamburger and drinking a Coke. It doesn’t make sense.
6. ちんぷんかんぷん(Chinpun Kanpun) /チンプンカンプン(Chinpun Kanpun)
ちんぷんかんぷん (chinpun kanpun) is used when you don’t understand the language someone is speaking or you don’t know what they are saying. It can be translated as “It’s all Greek to me” in English.
It is written in both hiragana and katakana.
Examples:
1. 健と隆史は日本語で話していたので私にはチンプンカンプンだった。
(Ken to Takashi wa nihongo de hanashiteita no de watashini wa chinpun kanpun datta.)
Ken and Takashi were talking in Japanese, so I had no idea what they were saying.
2. 健: 今日の授業は面白かったね。
Ken: (Kyō no jugyō wa omoshirokatta ne.)
Ken: Today’s class was very interesting, wasn’t it?
花子: 専門用語が多すぎて私にはちんぷんかんぷんだったわ。
Hanako: (Senmon yōgo ga ōsugite watashi ni wa chinpun kanpun datta wa.)
They used too many technical terms, so I didn’t understand. It was all Greek to me.
6. 知らない (Shiranai) / 知りません (Shirimasen): I Don’t Know
知る (shiru) means “to know” in Japanese. When you want to say “I don’t know,” you can change this verb into the negative form, 知らない (shiranai).
You can say 知らない (shiranai) to others, but it is better to use the polite form, 知りません (shirimasen) when speaking to someone you don’t know well. 知らない (shiranai) sounds a little cold, and it has another meaning.
Instead of using the polite 知りません, you could also use です to say “知らないです (shiranai desu).” This phrase is still polite, but sounds a little more casual than 知りません.
知らない (shiranai) is also a common way to say, “I don’t care” or “whatever.” Because of this, it is better to use the polite form, 知りません (shirimasen), with people who are not your close friends and family. If using the casual 知らない (shiranai), men or women can add the particle よ (yo) after it to make it sound a little softer. Females can add the feminine わ (wa) particle after 知らない for the same effect.
Shiranai and shirimasen are usually written in kanji like this: 知らない / 知りません
Examples:
1a. 健: 僕の鍵どこにあるか知らない？
Ken: (Boku no kagi doko ni aru ka shiranai?)
Ken: Do you know where my key is?
智子 (女性): 知らないよ。/ 知らないわ。
Tomoko (josei): (Shiranai yo. / Shiranai wa.)
Tomoko (female): I don’t know.
1b. 健: 僕の帽子どこにあるか知らない？
Ken: (Boku no bōshi doko ni aru ka shiranai?)
Ken: Do you know where my hat is?
隆史 (男性): 知らないよ。
Takashi (dansei): (Shiranai yo.)
Takushi (male): I don’t know.
2. 先生: 今日は道子が来ていないみたいですが、誰か知りませんか？
Sensei: (Kyō wa Michiko ga kiteinai mitai desu ga dare ka shirimasen ka?)
Teacher: It seems Michiko is not here today. Does anyone know about her?
生徒たち: 知りません。
Seitotachi: (Shirimasen.)
Students: We don’t know.
7. 知らん (Shiran): I Dunno
It seems that 知らん (shiran) is mainly used in western Japan. 知らん (shiran) can sound a little cold if said bluntly or aggressively, so being careful of how you say it and the tone of your voice is essential when using this word.
The meaning and usage of 知らん (shiran) are the same as 知らない (shiranai). 知らん (shiran) should also never be used in formal situations or with people of high status.
Examples:
1. 健: 僕の鍵どこにあるか知らない？
Ken: (Boku no kagi dokoni aruka shiranai?)
Ken: Do you know where my key is?
智子: 知らん。
Tomoko: (Shiran.)
Tomoko: I dunno.
2. 健: 僕の帽子どこにあるか知らない？
Ken: (Boku no bōshi dokoni aruka shiranai?)
Ken: Do you know where my hat is?
隆史：知らん。
Takashi: (Shiran.)
Takashi: I dunno.
Formal/Polite Ways to Say “I Don’t Know” in Japanese
Now let’s take a look at formal and more polite ways to say “I don’t know” in Japanese.
1. 初めて~ます (Hajimete~ Masu): This is My First Time To~ (So I Am Unsure Of It)
This expression means, “This is the first time I’m doing ~.” Using this expression implies that you don’t know much about something.
You can use this expression with verbs such as 聞く(kiku), 食べる (taberu), 見る (miru), etc. Let’s look at some examples.
Examples:
1. 道子: たこ焼きを知っていますか？
Michiko: (Takoyaki o shitteimasu ka?)
Michiko: Do you know what takoyaki is?
トム:いいえ。初めて見ます / 食べます / 聞きます。
Tomu: (Iie. Hajimete mimasu / tabemasu / kikimasu.)
Tom: No, this is the first time I’ve seen it / eaten it/ heard of it.
2. 智子: この花の名前を知っていますか？
Tomoko: (Kono hana no namae o shitteimasu ka?)
Tomoko: Do you know the name of this flower?
トム: いいえ。初めて見ます。
Tomu: (Iie. Hajimete mimasu.)
Tom: No, this is the first time I have seen it.
3. 健: この楽器を知っていますか？
Ken: (Kono gakki o shitteimasu ka?)
Ken: Do you know this instrument?
トム: いいえ。初めて見ます。
Tomu: (Iie. Hajimete mimasu.)
Tom: No, this is the first time to see it.
2. 心当たりがない (Kokoro Atari Ga Nai): To Have No Idea About Something
This expression is used when you “don’t have a clue” about something. In English, it can be translated as “I have no idea.” This expression is less direct and “softer” than saying 分かりません (wakarimasen) or 知りません (shirimasen), so it is often used in more formal situations.
Examples:
1. 道子: これ買ったの健なの？
Michiko: (Kore katta no Ken na no?)
Michiko: Did you buy this, Ken?
健: 心当たりがないな。
Ken: (Kokoro atari ga nai na.)
Ken: I have no idea.
2. 道子: 智子を探しているんだけど、見つからないの。彼女がどこにいるか知らない？
Michiko: (Tomoko o sagashite irun dakedo mitsukaranai no. Kanojo ga doko ni iru ka shiranai ?)
Michiko: I’m looking for Tomoko, but I can’t find her. Do you have any idea where she is?
健: 心当たりがないな。
Ken: (Kokoro atari ga nai na.)
Ken: I have no idea.
3. 道子: 彼女が誰か知ってる？
Michiko: (Kanojo ga dare ka shitteru?)
Michiko: Do you have any idea who she is?
健: 心当たりがないな。
Ken: (Kokoro atari ga nai na.)
Ken: I have no idea.
3. 身に覚えがない (Mi Ni Oboe Ga Nai): Not Having a Memory of Something
This expression is often used to deflect guilt or avoid responsibility for your actions.
If you want to emphasize that you don’t know or you didn’t do anything wrong, you can use 全く (mattaku) with this phrase: 全く身に覚えがない (mattaku mi ni oboe ga nai.) – I have absolutely no memory of that.
Examples:
1. 道子: 健！私のチョコレート食べたでしょ！
Michiko: (Ken! Watashi no chokorēto tabeta desho!)
Michiko: Ken! You ate my chocolate, right!?
健: 身に覚えがないよ！
Ken: (Mi ni oboe ga nai yo!)
Ken: I don’t know (what you’re talking about)!
2. 妻: あなた、今日は仕事だって言ってたのに、女の人とランチしてたわよね? 私見たのよ！
Tsuma: (Anata, kyō wa shigoto datte itteta noni onna no hito to ranchi shiteta wa yo ne? Watashi mita no yo!)
Wife: You said you had to work today, but you were having lunch with a woman, weren’t you? I saw you!
夫: 全く身に覚えがないよ！
Otto: (Mattaku mi ni oboe ga nai yo!)
Husband: I have absolutely no idea (what you’re talking about)!
3. 先生にカンニングの容疑をかけられたが、全く身に覚えがない。
(Sensei ni kanningu no yōgi o kakeraretaga mattaku ni mi oboe ga nai.)
I was accused of cheating by my teacher, but I have absolutely no idea what he’s talking about.
4. 分かりかねます (Wakari Kanemasu): I Am Unable to Undersrand
This is a very formal and polite expression that can be used in business for formal settings. In business settings, it can be rude to say “知りません (shirimasen)” since it is rather blunt and direct. Instead, we often say 分かりかねます (wakari kanemasu) because it sounds less direct and is more formal/polite.
This expression has a nuance of “something difficult to figure out/understand even after trying.”
Example:
Your client calls you over the phone:
お客: 今日届くはずの荷物がまだ届いていないのですが、どうなっていますか？
Okyaku: (Kyō todoku hazu no nimotsu ga mada todoiteinai no desu ga dō natte imasu ka?)
Client: The package that was supposed to come today has yet to arrive. What’s the status of the package?
道子: 申し訳ございません。私では分かりかねますので、担当者にすぐに確認いたします。
Michiko: (Mōshiwake gozaimasen. Watashi dewa wakari kanemasu no de tantōsha ni sugu ni kakunin itashimasu.)
Michiko: I apologize for the inconvenience. I’m unsure about the shipment’s status, so I will check with the person in charge immediately.
5. 面識がない (Menshiki Ga Nai): I Believe We Haven’t Met
面識がない (menshiki ga nai) is an expression used when haven’t met someone (yet). This expression is polite, which makes it suitable for formal situations.
This expression can be made even more polite by using the negative-masu-form like this 面識がありません (menshiki ga arimasen).
Example:
道子: 花子ちゃんのお母さんを知っていますか？
Michiko: (Hanako chan no okāsan o shitteimasu ka?)
Michiko: Do you know Hanako’s mother?
洋子: いいえ。面識がありません。
Yōko: (Iie. Menshiki ga arimasen.)
Yoko: I believe we have never met.
6. 存じ上げない (Zonji Agenai): I Am Not Sure Who That Person Is
存じ上げない (zonji agenai) is another formal and very polite way to say that you don’t know someone. It is 謙譲語 (kenjōgo), which is a humble form used to show respect to the person you are speaking with.
You can make this expression even more polite by using the negative masu-form like this: 存じ上げません (zonji agemasen). While this expression simply means “I do not know {person},” it is very polite and takes on a nuance of “I believe we have never had the pleasure of meeting.”
The difference between this expression and 面識がない (menshiki ga nai) is that 存じ上げない (zonji agenai) means you have