Translation guide
In Japanese, expressing supposition involves various grammatical patterns and words that convey conjecture, assumption, or guesswork. The choice depends on the level of certainty, formality, and whether the supposition is based on evidence or intuition.
It will probably rain tomorrow.
He has probably already gone home.
The polite form of 〜だろう, used in formal situations or when speaking politely.
It will probably rain tomorrow.
This problem is probably difficult.
Expresses possibility or uncertainty, similar to 'might' or 'maybe'. Less certain than 〜だろう.
He might not come.
That might be true.
Indicates a strong supposition based on logical reasoning or expectation, similar to 'should' or 'ought to'.
He should have arrived by now.
You should get better if you take this medicine.
Expresses a strong conviction or supposition, similar to 'must be' or 'no doubt'. More emphatic than 〜はずだ.
That person must be Japanese.
He must be lying.
Expressing a guess based on what you see or hear, often using sensory evidence.
Attached to verb stems or adjective stems to indicate that something looks or seems like it will happen or is the case, based on direct evidence.
It looks like it's going to rain.
This cake looks delicious.
Indicates a supposition based on sensory or situational evidence, similar to 'it seems that'. More subjective than 〜そうだ.
A more colloquial version of 〜ようだ, used in casual conversation to express supposition based on evidence.
It looks like that store is closed.
Expressing a supposition about a hypothetical or counterfactual situation.
Used to present a hypothetical supposition, meaning 'if we suppose that...' or 'assuming that...'.
If he were to come, what time would he arrive?
If that were true, it would be serious.
Similar to 〜としたら, but slightly more formal or written. Used for hypothetical suppositions.
If he is the culprit, what would his motive be?
Another variation for hypothetical supposition, often interchangeable with 〜としたら and 〜とすれば.
If it rains tomorrow, the game will be canceled.
Using adverbs to express uncertainty or conjecture.
The most common adverb for 'probably' or 'maybe'. Often used with 〜だろう/でしょう.
He will probably come.
It's probably okay.
A more formal or written word for 'probably' or 'perhaps', often implying a higher degree of likelihood.
Expresses a lower probability, similar to 'maybe' or 'possibly'. Often used with 〜かもしれない.
〜だろう indicates a higher degree of certainty than 〜かもしれない. Use 〜だろう when you are fairly confident, and 〜かもしれない when you are less sure or want to sound more tentative.
He will probably come. (I'm quite sure.)
He might come. (I'm not sure.)
〜そうだ is used for immediate, sensory-based guesses (looks like it's about to rain). 〜ようだ/〜みたいだ is used for more subjective inferences based on evidence (seems like someone is there). In casual speech, 〜みたいだ is more common than 〜ようだ.
He seems to be tired.
彼女は怒ってるみたいだ。
She seems angry.
恐らく、彼は成功するだろう。
He will probably succeed.
もしかしたら、彼は来ないかもしれない。
Maybe he won't come.
It seems it rained. (seeing wet ground)