～んです can be difficult for Japanese learners to use correctly. Grammatically, it’s easy to use it: ～んです simply just comes after the dictionary form of a word, and it always comes at the end of a sentence or phrase. So what makes it so problematic for learners? The answer is that ～んです has a social function, so the trick is knowing when it’s appropriate to use it.
んだ can be used to emphasize something that you think the other person should already know.
- “How many times do I have to say it before you understand?!? I don’t want to go!”
7. 言い換え： “To put it another way…”
After expressing something, you can put んです at the end of a second statement that either paraphrases or elaborates on the first one.
- “I got divorced yesterday. That means that from today on, I’m free!”
(While standing in front of a closed shop)
- “It’s Sunday so that means the shop is closed today… And after I came all the way here!”
- Person A : 「あの人、左薬指に指輪をしてるってことは結婚してるんだね。」
- “As for the ring on that person’s left finger--they’re married, right?”
- Person B : 「本当だね。」
- “That’s right.”
8. 一方的な提示（聞き手に話しかける／聞き手に話しかけるようなスタイル）：When making a statement, to indicate that you’re communicating to the listener(s)
When a person is making a one-sided statement, such as a lecture, presentation, or announcement to other people, んです is often added to the end of sentences to indicate that you’re addressing the listeners.
- “This is sudden but, I’m getting married soon.”
Listen up, Japanese learners!
The reason it is so important to use んです correctly is because it can convey certain social nuances. Because んです often implies an explanation or expectation (see usage #1), a simple sentence can become rude when んです is added inappropriately.
For example, consider this (incorrect!) expression:
The speaker of this sentence is trying to say “Could you lend me a book?”, but what it actually sounds like is “Why won’t you lend me a book?” Adding んです when making this request implies that you want an explanation because you expect the listener to say no.
A common mistake by learners is to add んです to the wrong types of questions. It indicates that you already have a belief or expectation about the other person, so the question becomes a bit rude. For example, if you want to ask what everyone’s opinion is, you should say:
However, imagine a learner who inappropriately adds んです , as shown below.
This question, “Don’t you have an opinion?”, has the tone of demanding an explanation. It sounds like you think people either don’t have an opinion, or you’re wondering why they aren’t saying anything. (Here, んです adds the nuance of explanation or expectation, so when you add it after asking people if they have an opinion, it becomes something like, “Why don’t you have an opinion?” Like this: 「どうして何も意見を言わないのか？」)
One way to think of this is to watch what inserting んです does here:
- “That bags looks heavy. Are you going on a trip?
By adding んです at the end, you’re letting the listener know that you think they’re going on a trip, and you want them to confirm your assumption. However, in different situations, adding んです at the end of certain questions might inadvertently become rude because of the added nuance (e.g., assumptions, demanding an explanation). It isn’t rude to assume that someone with a heavy-looking bag is going on a trip, so it’s appropriate to use んです in this sentence.
When you’re talking or writing to another person, the incorrect addition of んです can create the feeling of a one-sided statement (usage #8). A common mistake made by Japanese learners is to put んです at the end of a request, with the intention of usage #4 but it accidentally adopts the nuance of #8 instead. For example, consider a student who is writing to a potential italki teacher for the first time and wants to request conversation practice. Below are two incorrect (i.e., accidentally rude) sentences with んです, followed by the correct, polite version.
- 「 はじめまして、私の名前は〜です。会話練習したいんです。ありがとう。」
- “Nice to meet you. My name is ~. (I’m telling you) I’d like to do conversation practice. Thanks.”
- 「 はじめまして、私の名前は〜です。会話練習したいと思っているんです。ありがとう。」
- “Nice to meet you. My name is ~. (I’m telling you) I think I’d like to do conversation practice. Thanks.”
- 「 はじめまして。私の名前は〜です。会話の練習をしたいと思っています。よろしくお願いします。」
- “Nice to meet you. My name is ~. I think I’d like to do conversation practice. Thank you in advance.”
In the first two sentences, the student is trying to frame it as a request, but this particular sentence structure sounds like a one-sided address (“I’m telling you…”). Unfortunately, this becomes a bit rude. If this sentence occurred in the middle of a conversation after the student was asked a question (e.g., usage #1), then it might be appropriate. However, in this particular context it adopts a very different nuance.
The nuance created by using んです depends on the context and the content of the conversation, so it is important to be careful when using it.