Practice JLPTHow to tell them apart
The core contrast is certainty level: でしょう/だろう expresses a confident guess with moderate probability, while かもしれない expresses genuine uncertainty, acknowledging a real possibility that could go either way. Swapping them feels off because かもしれない downplays what you're fairly sure of, and でしょう overstates what you're unsure about. For instance, 雨が降るでしょう sounds like a weather forecast, whereas 雨が降るかもしれない sounds like a mere possibility.
- だろう Use でしょう/だろう when you lean toward a likely outcome without hard evidence.
- かもしれない Use かもしれない when you genuinely can't tell and want to flag a real possibility.
| Grammar point | Meaning | JLPT level |
|---|---|---|
| だろう darou | Probably/I think | N4 |
| かもしれない kamoshirenai | Might/Maybe | N4 |
だろう darou
Probably/I think
Probably | An auxiliary indicating the speaker’s conjecture which is not based on any particular information or evidence.
-
あのアパートは高いでしょう。
That apartment is probably expensive.
-
あの人は中国人だろう。
That man is probably Chinese.
かもしれない kamoshirenai
Might/Maybe
Might | Can't tell if ~
-
あの人は今日のパーティーのことを忘れたかもしれません。
He might have forgotten about today's party.
-
あの先生の授業はつまらないかもしれない・かもしれません。
That teacher's class might be dull.
だろう and かもしれない are both JLPT N4 grammar points that Japanese learners often mix up. This page compares them side by side — meanings, usage and example sentences — so you can tell them apart.