かもしれない (kamo shirenai)

Related patterns12

Similar

でしょう
かもしれない keeps the odds at fifty-fifty or lower, just "might". でしょう leans toward yes, more like "probably".
どうも
かもしれない keeps several possibilities open (風邪かぜかもしれない). どうも says the speaker already leans one way, without knowing why (どうも風邪かぜらしい).
かな
かもしれない states the maybe as a fact, in any speech level (かもしれません). かな instead asks yourself, stays casual only, and has no polite form (でしょうか instead).
かねない
かもしれない is neutral and can follow almost anything (危険きけんかもしれない). かねない follows a verb's ます-stem, and always warns the outcome is bad (危険きけんになりかねない).
もしかしたら〜かもしれない
かもしれない just states a plain possibility. もしかしたら flags it early as the long shot, not the expected one.
ないとも限かぎらない
かもしれない floats a plain possibility (雨あめが降ふるかもしれない, a forecast). ないとも限かぎらない reaches the same idea to argue for acting (雨あめが降ふらないとも限かぎらない, take the umbrella).
のではないか
かもしれない rates the guess as only possible, with no answer expected (遅おくれるかもしれない). のではないか rates it as likely, and asks you to agree (遅おくれるのではないか).
恐おそれがある
かもしれない is neutral, good or bad, and fits speech (明日あした晴はれるかもしれない). 恐おそれがある only names unwelcome outcomes, and is written (津波つなみの恐おそれがある).
せいか
かもしれない doubts the whole claim, even the rain itself (雨あめが降ふるかもしれない). せいか doubts only the cause, and states the result flatly (疲つかれているせいか字じが汚きたない).
たぶん
たぶん bets on the case the speaker expects (たぶん来こない forecasts an absence). かもしれない just names one possibility not ruled out (来こないかもしれない).
ような気きがする
ような気きがする is a felt hunch, with no stated evidence ("something tells me"). かもしれない instead states a bare possibility, evidence or none.

Lookalikes

はずがない
かもしれない's ない is frozen and never turns the meaning negative (来くるかもしれない). はずがない's ない really negates, ruling the chance out (来くるはずがない).

Same meaning15

probably; might; should be

だろうprobably; I suppose (plain style)attaches at
でしょうprobably; I suppose; right?attaches at
はずだshould; ought to; is supposed toattaches at
かなI wonder; maybe (wondering aloud)attaches at
かねないcould well (and it wouldn't be good); there's a real chance thatattaches at
まいsurely won't; I shall never — the classical negative of だろう and of （よ）うattaches at
ないとも限かぎらないyou can't rule out that it will happen; it may happen anywayattaches at
に違ちがいないmust be; surely is (a confident conclusion)attaches at
に決きまっているof course it is; is bound to be — treated as beyond argumentattaches at
に相違そういないbeyond doubt; there is no doubt that (written, formal)attaches at
恐おそれがあるthere is a danger that; is at risk of (something unwelcome)attaches at
そうもないshows no sign of; doesn't look like it willattaches at
と考かんがえられるit can reasonably be concluded that; is to be regarded asattaches at
と思おもうI think that; in my opinionattaches at
ような気きがするI have a feeling that; it seems to me thatattaches at

All examples4

might; may — flags a mere possibility without leaning either way

午後ごごから雪ゆきになるかもしれません。
gogo kara yuki ni narukamoshiremasen.
It might turn to snow in the afternoon. formal
明日あした、ちょっと遅おくれるかも。
ashita, chotto okureru kamo.
I might be a bit late tomorrow. casual
鍵かぎを会社かいしゃに忘わすれてきたかもしれない。
kagi o kaisha ni wasurete kita kamo shirenai.
I may have left my keys at the office. neutral
この靴くつは私わたしには少すこし大おおきいかもしれません。
kono kutsu wa watashi ni wa sukoshi ookii kamo shiremasen.
These shoes might be a little too big for me. neutral

How it's formed4

All forms4

かもkamocontraction
味あじわうかも
a casual short form used at the end of a sentence. You'll hear it as 遅おくれるかも。
かもしんないkamoshinnaicolloquial
味あじわうかもしんない
a relaxed, fast pronunciation of しれない. You'll hear it in casual speech.

pastかもしれなかったkamoshirenakatta
味あじわうかもしれなかった
politeかもしれませんkamoshiremasen
味あじわうかもしれません

Notes

The ない here never turns the meaning negative — negate inside instead
(来こないかもしれない). It goes straight on nouns and な-adjectives, no だ needed (雨あめかもしれない).