Why: なぜ, どうして, & なんで
In this lesson, we will focus primarily on the ways to say “why” in the interrogative sense of the word. Aside from differing in politeness level, the various ways to say “why” themselves are sensitive to tone, in which case medium – whether we are talking about the spoken language or the written language – will also be a major factor in how to use them correctly.
なぜ
Etymologically speaking, the core word for “why” in Japanese is なぜ, written in kanji as 何故. In large part, なぜ is preferred in objective questions. So long as that message gets across, it may be seen in all speech styles; however, tone will drastically change how なぜ-questions are perceived.
Unlike English, Japanese does not exhibit what is known as “wh-movement” in which the interrogative is brought to the front of the sentence. In Japanese, interrogatives are treated as adverbs, and as adverbs, they may float, not always necessarily showing up in sentence-initial position. Granted, it is still very common for them to appear there, but if the topic of the sentence has more significance within the question like in Ex. 3, なぜ will appear in sentence-medial position.
1. なぜ地球は丸いのですか。
Why is the Earth round?
2. なぜ方言や訛りなどが生まれたのですか。また、なぜ東京の方言は標準語なのですか。
Why do dialects, accents, and the like come into existence? Also, why is the dialect of Tokyo the standard dialect?
3. 空はなぜ青いの？
Why is the sky blue?
Grammar Note: As Ex. 3 demonstrates, the topic and なぜ can be flipped with no changes made to particle usage in the sentence.
4. なぜワシントン州に引っ越すんですか。
Why did you move to the State of Washington?
Grammar Note: Ex. 4 would be spoken, not written. The question innocently asks why the person in question moved to the State of Washington. The question does not imply interrogation or pressure for the person to spill some sort of truth.
A college classmate lover began dating another woman, and she couldn’t fathom that she herself was dumped and why the person chosen was some other person and not herself.
5. ちなみになぜこの商品を気に入って頂いたのですか？
By the way, why did you take interest in this product?
6. お金が貯まる人はなぜ時間の使い方がうまいのか。
Why is it that people whose money is being saved up good at using time?
Nuance Note: Ex. 6 sounds as if it is a header to some document/post. It is not the plain speech のか that you hear in coarse conversations. That usage is to be seen shortly in this lesson.
7. 同じアマゾン内で、同じ商品なのに価格が違うのはなぜですか。
In Amazon itself, why is it that something may be the same product but have a different price?
8. なぜ、この言葉を聞くと不快に思ってしまうのでしょうか？
“Why,” do you not feel uncomfortable when you hear this word?
Nuance Note: As with any word in Japanese, “why” can also be the word of conversation.
9. なぜなら、答えは、自分のすぐ「隣」にあったからです。
That is because the answer is right beside oneself.
Grammar Note: When used with the particle なら, なぜ is used to explain reasoning. You can see it as literally meaning “if you ask why…”
In Ex. 10 and Ex. 11, なぜ is used in embedded questions. It is typically the word of choice in this situation due its objective nature.
10. 彼女は、大学の同級生である恋人が、別の女と交際をはじめて、自分は捨てられた、なぜ選ばれたのが他方であり自分でないのかがどう考えても分からなかった。
A college classmate’s lover began dating another woman, and she couldn’t fathom that she herself was dumped and why some other person was chosen and not herself.
11. 皆がなぜ、いきなり集団ヒステリーのように泣き出したのか、不思議でたまらなかった。
It was a wonder to me why everyone started suddenly crying out in mass hysteria.
We as humans intuitively infer the tone of a question based on its content. Below, each example is confrontational. This is when なぜ will go from sounding objective and calm to sounding confrontational and out of anger.
12. 「なぜ遅刻をしたの？」
“Why were you late?”
13. 「なぜ気付かなかったの？」
“Why didn’t you notice?”
14. 「なぜ忘れてきたんだ？」
“Why did you come and forget it?”
なにゆえ
As you may have noticed, the characters of 何故 imply that it should normally be read as なにゆえ. It just so happens that this is also a valid reading, but it is an archaism. Its place in Modern Japanese is relegated to jokingly sounding old-fashioned like in Ex. 15 or in neo-classical contexts.
15. なにゆえここに君がいるのか。
Why is it that you are here?
どうして
どうして is likely the word for “why” you have incidentally heard over and over. This is because it is far more frequently emotionally based. It also happens to be somewhat more casual than なぜ as an effect.
This word is composed of どう meaning “how/in what way?” and して, the gerund of する. Thus, it intrinsically means “how.” This is demonstrated in the following examples.
16. 毎朝はどうして時間を潰そうかと考えていた。
Every morning I pondered how I would pass the time.
Grammar Note: When used with the volitional form + the particle か, the meaning of “how” becomes especially obvious.
17. どうして僕が試験に受かったって知ってますか？
Do you know how I passed the exam?
Sentence Note: When the sentence ends in “do you know…?” it makes more sense to interpret どうして as “how” rather than “why” because even if you were to rephrase the English translation to use “why” instead, the question still intrinsically revolves around method. This means that even なぜ to some extent may even ask “how” like in Ex. 18.
18. なぜ扇風機は働くのか.
How fans works/how do fans work/why (do) fans work(?)
Sentence Note: Even in English, there is some fluctuation that can be seen between “why” and “how.” The Japanese phrasing could be used in introducing a question of discussion or even as the title of something.
In related phrases, the literal breakdown of どうして meaning “how” becomes even more apparent; especially in どうしても, which either means “no matter what cost” or “no matter what,” the latter being used in a negative connotation.
19. どうしても君を失いたくない。
I don’t want to lose you no matter what.
20. どうしても納得できません。
I can’t accept this by any means.
Unlike all other words for “why,” どうして has evolved other usages. Occasionally, you will find it used in complex adverbial phrases with a meaning of “contrary to (expectations).”
21. なかなかどうしてうまくいかないものだ。
Things aren’t going well as expected.
Phrase Note: なかなかどうして is a set phrase which is synonymous with 思ったより.
22. ちょっと心配だったのですが、どうしてなかなかしっかりしてるよ。
I was a little worried, but (it’s) holding quite sturdy contrary to expectations.
Grammar Note: As you can see, for this meaning to make sense, the sentence itself must not be formed as a question but as a declarative statement. Furthermore, for どうして to be used for this meaning, it needs to be followed by some line that brings up a past expectation.
Another grammar pattern that works on the sense of “how” is どうして…られよう（か）. This utilizes the potential form with the ending よう, which you may remember as originally also being used to indicate “surely” like in だろう・でしょう. This means we get an expression on the lines of “how could…possibly…?” It is inherently rhetorical and emphatic.
23. そんな姿を見てどうして黙っていられようか。
How could one stay silent after having seen that appearance?
24. どうして忘れられよう。どうして忘れていられようか。
How could I forget? How I could I ever forget?
25. こんな世の中でどうして笑っていられようか。
How could one ever remain laughing in such a world as this?
26. どうして人の死を喜んでいられようか。
How could one ever be rejoiceful in the death of another person?
It may come as no surprise that at one point, どうして could also be used as an interjection similar to “oh my!” like in Ex. 27. This, however, is not so common nowadays, but it still readily understood due to its occasional use in writing.
27. どうして、大層な悪役ぶりだな。
Oh my, what the villain-type you are.
Now, you be may thinking, is どうして used to mean “how”? No, not quite… In the same way the concept of “why” and “how” are intertwined, so is the case with どうして. As a stand-alone sentence, all you need is どうして or the addition of ですか if used in semi-casual polite speech. However, when more is added to the sentence, some form of のか is grammatically necessary.
Remember that unlike なぜ, どうして tends to be emotionally and/or subjectively based. Although it is far more common in conversation due to its semi-casual nature, its overuse will draw upon more emotion than you intend.
28. どうしてですか。
Why (is that)?
29. どうしてまた遅くなったんですか。
Why were you late again?
30. どうして自分を男だと思うんですか。
Why do you see yourself as male?
31. 昨日、どうして来なかったの？
How come you didn’t come yesterday?
Sentence Note: As Ex. 31 demonstrates, it is sometimes more natural to translate どうして as “how come?” This makes the intertwined dichotomy of how-why even more apparent.
32. どうして泣くの。どうして泣き止まない。
Why do you cry? Why do you not stop…?
Sentence Note: The lack of のか, interestingly enough, creates a sense of despair. It also makes it clear that the sentence is part of the speaker’s inner monologue. The speaker is distraught. One can imagine the next thought of the speaker being tied to whatever troubles are besieging the person.
33. どうしてあくびが出るの？
Why are you yawning?
なんで
なんで is composed of 何 meaning “what” and the particle で, which can be seen as marking the instrumental case in this phrase. The instrumental case marks means/method. This means that なんで is akin to “how come?”
なんで is more casual than anything else. It doesn’t particularly have any sense of objectivity or subjectivity. This is why it is used heavily in casual conversation. However, just as with the other words for “why,” it too can be used in tense situations or in questions based in intimidation. Nevertheless, think of how teenagers say “why” and equate it to how people would generally use なんで. By doing so, and by reviewing the examples below, you should get a good picture of how なんで is used.
Grammatically speaking, a sentence with なんで ends with some form of のか. Without it, the question will sound brisk and abrupt. Of course, in a stand-alone sentence, it can be said by itself or followed by ですか in semi-casual speech.
34. 特に、人生経験、成功体験の少ない子どもたちに向かって、なんで？なぜ？どうして？の問いかけは百害あって一利なしです。
Especially towards child, who have little life experience and experience succeeding, questioning them with “why, why, why?” brings a hundred harms and not a single gain.
35. なんでテストで100点取ったんだ？
How come you got a 100 on your test?
Sentence Note: Ex. 35 is an example of how being asked about something good can sound intimidating when seemingly interrogating someone.
36. なんでちゃんとやらないの？
Why won’t you do it properly?
37. すごいじゃないか！なんでそんなによかったんだ？
Wow, that’s awesome! How come it was so good like that?
38. すごいですね！なんでそんなに好調なんですか？
Wow, that’s great! How come things are going so well?
39. なんでこれが起きた？
How come this happened?
40. なんでそうなった？
How did it end up that way?
41. なんで？なんで？
How come? How come?
42. なんでだよ！
How come!?
43. ねーねー？なんで？
Hey, hey… how come?
44. なんでじゃねーんだよ？
Don’t you “how come?” me; you hear me?
One grammatical situation that makes なんで very similar to なぜ but in a far more casual way is when it is used at the end of the sentence to mean “why is that/how come…?”
45. 人間が跳べないのは何でですか。
Why is it that/how come humans can’t jump up?
46. 同じ型の電車でも、ドアの開閉速度が異なるのは何でですか。
Why is that/how come the opening and closing speed of doors differ even when it’s the same model train?
47. 女と男の結婚率が違うのは何でですか。
Why is that/how come the marriage rates for men and women are different?
48. 店によって違うのは何でですか。
Why is that/how come it’s different based on the store?
49. 汗で白シャツの脇が黄色くなるのは何でなの？
Why is that/how come the sides of white T-shirts become yellow from sweat?
50. 形が違うのは何でですか。
Why is that/how come the shape is different?
理由
The word 理由, which literally means “reason,” may also be translated as “why” as in “the reason (why).” Given how the 連体形 works in Japanese, one can say it accounts for the “why” part of that translation. With that in mind, consider how the following sentences are translated.
51. 退職（した）理由を聞かせてください。
Please let me hear (the reason) why you left your (previous) job.
52. あなたが人を殺した理由を教えてください。
Please tell me (the reason) why you killed someone.