Translation guide
In Japanese, expressing speculation involves various grammatical patterns that convey degrees of certainty, inference, or hearsay. The most common and versatile is だろう／でしょう, used for conjecture. Other patterns like かもしれない express possibility, while らしい and みたい indicate hearsay or resemblance-based inference. The choice depends on the source of information and the speaker's confidence.
Express a personal guess or inference about a situation, often based on reasoning or intuition.
Polite form of だろう, used in formal speech or writing. Same conjecture meaning.
明日は雨でしょう。
It will probably rain tomorrow.
彼は来ないでしょう。
He probably won't come.
Literally 'I think that...', used to explicitly state personal speculation. Less direct than だろう.
明日は雨だと思う。
I think it will rain tomorrow.
Indicate that something is possible but not certain.
Expresses possibility or uncertainty. Can be used for both positive and negative outcomes.
彼は来るかもしれない。
He might come.
雨が降るかもしれない。
It might rain.
Casual abbreviation of かもしれない, common in spoken Japanese.
彼、来るかも。
He might come.
Convey that information is based on what you heard from someone else or on observable evidence.
Indicates hearsay or inference based on reliable information. Can also express typical characteristics.
Casual expression for 'seems like' based on direct observation or impression. Similar to ようだ but more colloquial.
彼、来ないみたい。
It looks like he's not coming.
More formal/literary version of みたい, expressing inference from evidence.
彼は来ないようだ。
It appears he's not coming.
Explicitly marks information as hearsay. Attaches to plain form. Note: different from the 'looks like' そうだ which attaches to verb stems.
彼は来ないそうだ。
I heard that he's not coming.
Express speculation in academic, journalistic, or formal writing.
Literally 'is seen as', used in news reports to indicate speculation or inference by observers.
景気は回復すると見られる。
The economy is expected to recover.
Means 'it is thought that', used for objective speculation in formal writing.
原因はウイルスだと考えられる。
The cause is thought to be a virus.
だろう expresses a higher degree of certainty (probably), while かもしれない expresses a lower degree (might). Use だろう when you have some basis for your guess, and かもしれない when you are simply acknowledging a possibility.
彼は来るだろう。（確信がある）
He will probably come. (I'm fairly sure)
彼は来るかもしれない。（可能性がある）
He might come. (It's possible)
Both indicate hearsay, but らしい can also be used for inference based on evidence, while そうだ is purely for reporting what you heard. らしい is more indirect and can imply the speaker's own judgment.
彼は来ないらしい。（聞いた情報＋推測）
It seems he's not coming. (Based on what I heard and my inference)
彼は来ないそうだ。（聞いた情報のみ）
I heard he's not coming. (Just reporting what I heard)