Translation guide
The English word "guess" covers a range of situations from casual speculation to formal conjecture. In Japanese, the best expression depends on whether you are making a rough estimate, a logical inference, or a random guess, and also on the level of certainty and formality.
To express a guess or hunch in everyday conversation, often with low certainty.
The most common way to say "I guess..." or "I think..." in casual speech. It softens the statement and shows it's just your opinion.
I guess it will rain tomorrow.
I guess he won't come.
A very casual sentence-ending particle used when wondering or guessing, often to oneself. Common in informal speech.
I guess this is okay.
A plain form used for conjecture, similar to "probably" or "I guess". Often used in masculine speech or writing.
I guess he's already gone home.
To express a guess based on evidence or reasoning, often with moderate to high certainty.
Indicates a strong expectation based on logic or information. "It should be..." or "I'm pretty sure..."
To guess a number, amount, or time without precise calculation.
To make a guess in a guessing game, test, or when trying to identify something.
To guess correctly, to hit upon the answer. Often used in games like "guess the number".
To express a guess in academic, professional, or formal settings.
English speakers often use 'I guess' as a filler or to soften a statement. In Japanese, directly translating this as 「私は推測する」 sounds unnatural. Instead, use 「〜と思う」 or 「〜かな」 to convey the same tentative feeling.
I guess that's probably the case.
推測 (suisoku) is a reasoned guess or estimate, while 当てずっぽう (atezuppō) is a wild, random guess. Use when you have some basis, and when you are just guessing blindly.
I wonder if it will be sunny tomorrow.
He should have arrived by now. / I'm pretty sure he's arrived.
The key should be here.
Expresses a strong conviction or guess, "must be" or "no doubt". Slightly more formal/literary.
That must be him.
Used when making a guess based on sensory evidence or observation. "It seems like..."
It seems like someone has come.
A noun meaning "guess" or "conjecture". Often used with する to mean "to guess" in a slightly formal or analytical context.
That's just a guess.
Guess his age.
A wild guess, a shot in the dark. Casual and often used when the guess is random.
I answered with a wild guess.
Attached to a number to mean "about" or "approximately". Used for rough guesses.
I guess it'll take about 30 minutes.
Please guess the answer.
Try to guess how old I am.
Deduction or reasoning, often used in mystery contexts. "To deduce" rather than a blind guess.
Guess who the culprit is. (Deduce)
Also used in formal contexts for conjecture or estimation.
According to experts' guesses...
Conjecture, speculation, often with a nuance of being groundless. Used in formal writing.
That's mere speculation.
I couldn't even guess.
Idiomatic