connective N3 common casualpolitewritten
〜からだ — it is because ~
〜からだ ・ からだ
Builds on 〜から
Meaning
- it is because ~ / the reason is that ~ — gives the reason as a standalone sentence, after the situation it explains
Key sentence
遅刻した。電車が止まったからだ。
I was late. It's because the train stopped.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Clause (plain form) + から | … から + だ (です for polite) | 疲れているからだ / 安いからです |
Examples
彼が成功したのは、努力を続けたからだ。
The reason he succeeded is that he kept making an effort.
値段が高いのは、材料がいいからです。
It's expensive because the ingredients are good.
When you can't use it
- からだ ends a sentence to supply the reason for what was just stated, so it stands after the result, not before it. To attach a reason inside a single sentence ('because X, Y'), use plain から/ので instead.
Easily confused with
から Embedded から links reason and result in one sentence (遅れたから謝った). からだ closes a separate sentence that explains a previously stated fact ('… It's because ~'). なぜなら なぜなら opens the explanation ('the reason is…') and typically closes with からだ. They work as a pair: なぜなら … からだ. わけだ わけだ draws a conclusion that makes sense of a situation ('that's why ~, no wonder'). からだ states the cause itself ('it's because ~'); わけだ states the resulting realization.
See 〜からだ in real sentences
Jengo shows 〜からだ 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 Intermediate Japanese Grammar.