Low-Confidence Guessing
かもしれない says something is possible — maybe 50%, maybe less. It is the weakest of the guessing patterns, weaker than でしょう and much weaker than はず.
- 明日雨が降るかもしれません。(It might rain tomorrow.)
How to Attach It
Use the plain form, and drop だ from nouns and な-adjectives:
| Type | Plain | + かもしれない |
|---|---|---|
| Verb | 降る | 降るかもしれない |
| い-adjective | 高い | 高いかもしれない |
| な-adjective | 暇だ | 暇かもしれない |
| Noun | 学生だ | 学生かもしれない |
That dropped だ is the usual mistake — ×学生だかもしれない.
Politeness
かもしれません is the polite form. In casual speech it shortens hard:
- かもしれない → かもしれん → かも
雨降るかも。 is completely normal spoken Japanese.
How Sure Is Each Guess?
| Pattern | Confidence |
|---|---|
| かもしれない | might — 30–50% |
| でしょう・だろう | probably — 60–80% |
| はず | should be — expectation from evidence |
| に違いない | must be — near certainty |
A Softening Device
Because it lowers your commitment, かもしれない also softens opinions and disagreement:
- それは違うかもしれません。(That might not be right.)
Compare the blunt それは違います。 This is the same politeness move as と思う.
Past Guesses
Put the inner verb in the past, not かもしれない:
- ○ もう帰ったかもしれません。(They might have gone home already.)
- × もう帰るかもしれませんでした。