N4 · Probability and hearsay
かもしれない: might
the possibility かもしれない
A plain form plus かもしれない: it is possible, but far from sure.
かもしれない follows the plain form of a verb or i-adjective — 来るかもしれない, 来ないかもしれない, 高いかもしれない — and comes straight after a noun or a na-adjective, without だ: 雨かもしれない, 暇かもしれない. The polite form is かもしれません. It is normally written entirely in kana.
It says that something is possible and cannot be ruled out, with a chance of about half or less. That makes it weaker than でしょう: a forecaster who says 雨でしょう expects rain, one who says 雨かもしれません is warning you about it. もしかしたら or もしかすると at the start, "perhaps", makes the doubt explicit.
Because it is non-committal, かもしれない is one of the main tools of polite speech. ちょっと難しいかもしれません, "it might be a little difficult", is very often a gentle "no". Opinions are softened with it too: 私の考えは違うかもしれませんが, "I may see it differently, but".
English "may" means both "might" and "is allowed to". かもしれない only ever means the first. "You may go home" in the sense of permission is 帰ってもいいです; 帰るかもしれません would mean "you might go home, who knows".
The form
| verb, plain | 来るかもしれない |
| verb, plain past | 来たかもしれない |
| verb, negative | 来ないかもしれない |
| i-adjective | 高いかもしれない |
| na-adjective (no だ) | 暇かもしれない |
| noun (no だ) | 雨かもしれない |
| polite | 雨かもしれません |
| casual | 雨かも |
The rules one by one
The form this topic is aboutThe word that calls for it
Verbs and i-adjectives take かもしれない after the plain form.
電車が遅れるかもしれません。The train might be late.
Nouns and na-adjectives take it directly, without だ.
あの人は先生かもしれません。That person might be a teacher.
The polite form is かもしれません.
明日は行けないかもしれません。I might not be able to go tomorrow.
It is weaker than でしょう: a real possibility, not an expectation.
もしかしたら、雪が降るかもしれません。It might possibly snow.
In casual speech it shortens to かも.
あ、財布を忘れたかも。Oh, I might have forgotten my wallet.
A closer look
A scale of certainty
The patterns in this area can be lined up by how sure the speaker is. At the bottom stands かもしれない, "it might be". Above it でしょう, "it probably is". Higher again はず, "it should be, given what I know", and at the top に違いない, "it must be".
English speakers tend to translate every "maybe" with かもしれない and every "probably" with でしょう, which works well enough. What is easy to miss is how often a Japanese speaker uses one of them where English would simply state the fact — and that a sentence without any of them can sound more certain than you intended.
How to spot it
- かもしれない
- かもしれません
- かも
- もしかしたら
- もしかすると
Example sentences
午後は雨が降るかもしれません。It might rain in the afternoon.
道が混んでいるので、少し遅れるかもしれません。The roads are busy, so I might be a little late.
その話は本当かもしれません。That story might be true.
彼女はもう寝ているかもしれません。She might be asleep already.
この靴は私には小さいかもしれません。These shoes might be too small for me.
鍵をかけなかったかもしれない。I might not have locked the door.
7 more example sentences
もしかしたら、電話番号が違うかもしれません。Perhaps the phone number is wrong.
急げば、まだ間に合うかもしれない。If we hurry, we might still make it.
答えが間違っているかもしれません。The answer might be wrong.
来年、大阪に引っ越すかもしれません。We might move to Osaka next year.
熱があるね。風邪かもしれないよ。You have a temperature. It might be a cold.
明日は会社が休みかも。The office might be closed tomorrow.
その店は月曜日は閉まっているかもしれません。That shop might be closed on Mondays.
Worth knowing (1)
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A polite way of saying no
Asked whether something is possible, a Japanese speaker will rarely say できません outright. ちょっと難しいかもしれません leaves room for both sides and is understood as a refusal. Taking it literally and waiting for an answer is a classic misunderstanding.
その日はちょっと難しいかもしれません。That day might be a little difficult.
The trap English speakers fall into
Watch out
The plain form of 雨です is 雨だ, so "plain form plus かもしれない" seems to give 雨だかもしれない. But after a noun or a na-adjective the だ drops out, exactly as it does before でしょう.
かもしれない means might: a real chance, no promise.
Your turn
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