んです (or んだ, のです, のだ) is a blind spot in Japanese language education for foreigners. Textbooks seldom talk about this phrase. And even if it is mentioned, students are usually only taught about the sentence structure, which is pretty useless and hopeless, considering that its sentence structure cannot be easier, i.e. we only need to add it to the end of a sentence. Students, however, must learn in what situations they should use this phrase in order to make their Japanese more natural to native speakers. I repeat. Students should learn situations as well, not just sentence structures. And this article is to tell you about those situations.
Actually, even native teachers tend to avoid teaching this phrase, because it does not have any counterpart in English. After Japanese to English translation, usually this phrase will disappear. It seems that using or skipping this phrase will not make any big difference. And as a matter of fact, native speakers will still understand you even if you skip all んです in your sentences. As a result, a lot of learners choose to go the easy way and build a very bad habit of using unnatural Japanese, because んですis in fact used very frequently in everyday Japanese. In my opinion, its frequency is as high as English “will”. Just imagine how English will sound like if a foreigner skips all ‘will’ in his English.
This foreigner will sound funny, won’t he? In order not to make you sound funny when you speak Japanese, here I have listed 6 situations in which んです should be used. All information is based on an article written by Prof. Tanomura Tadaharu from Osaka University. The article was publish in 1990.
“A” means a sentence that does NOT have んです.
“B” means a sentence that HAS んです
6 situations in which you should use んです
B is the reason for A
Translation: The flower has withered, because I forgot to water it.
Explanation: In this situation, んです is used to explain the previous sentence. It can be translated as “because” in English.
B is used to describe A from another angle or summarize A.
Translation: She is not married. Nor does she have any boyfriend. In other words, she is single.
Explanation: んです here can be translated as “in other words” or “that is”. It usually follows つまり(that is), 私が言いたいのは(what I want to say is) and 要するに (in short).
A is a scene or an implied situation. B is deduced from A. In this situation, the whole sentence A sometimes is skipped.
Example: (I see that the ground is wet) 雨が降ったんです。
Translation: (I see that the ground is wet) It rained.
Explanation: In this example, the whole sentence A is skipped. Only sentence B is spoken or written. And B is a conclusion based on the observation of A. んです implies that the speaker has such observation.
B is the result of A.
Translation: I look up at the cloudy sky, then I see snow fall.
Explanation: A happens and as a result B happens. んです here can be translated as “then / as a result”.
B is an order. A does not exist.
Translation: Come here quickly.
Since it is an order, normally we don’t use the polite ですform. んだ here make this sentence become an order.
To tell listeners your decision. A does not exist.
Translation: Even if my parents disagree, I’ll do it.
Explanation: んです here can be used to show resolution and judgment.
6 situations in which you can’t use んです
1. Something occurs suddenly / unexpectedly
Translation: Oh! My wallet is gone.
Explanation: Because it happens unexpectedly, you should not use んです. However, if a friend of yours see that you are unhappy and ask you why, you can say 財布を紛失したんです.
2. You are telling people how you feel
Translation: Ah! I’m so tired.
3. An immediate decision
Translation: I’ll go too.
4. You are not sure
Translation: I think Taro can win. No. Maybe he’ll lose.
5. One-way conversation such as news broadcast
Translation: If you move an inch, I’ll shoot.
Translation: What is the day of the week today? It’s Friday today.