modality N5 essential casualpolite
んです — explanatory のだ (polite spoken)
んです
Meaning
- it is that ~ / the reason is that ~ — the polite-spoken form of explanatory のだ
Key sentence
すみません、道が分からないんです。
Excuse me — the thing is, I don't know the way.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Verb / i-adjective (plain form) | plain + んです | 分からない → 分からないんです |
| Noun / na-adjective (plain) | N/na-adj + なんです | 初めて → 初めてなんです |
When: The everyday polite-spoken form; のです (uncontracted) is more formal/written, んだ is its casual form.
Examples
今日は少し疲れているんです。
It's that I'm a little tired today.
これ、どうやって使うんですか。
How do you use this? (asking for an explanation)
実は、お願いがあるんです。
Actually, the thing is, I have a favor to ask.
Easily confused with
Notes
- The question form 〜んですか asks the listener to explain or account for something. It can sound prying if the matter isn't really yours to ask about — tone and context matter.
See んです in real sentences
Jengo shows んです the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Basic Japanese Grammar.