Translation guide
Expressing low, indistinct speech, often to oneself or in complaint.
Speaking quietly to oneself, often while thinking or reading.
The most common and neutral verb for muttering to oneself. Often used for quiet, solitary speech.
彼は独り言を呟いた。
He muttered to himself.
Literally 'to say a soliloquy'. A common phrase for talking to oneself, often used when the muttering is audible.
彼女はよく独り言を言う。
She often mutters to herself.
Muttering in a low, continuous, and often complaining manner. Slightly more negative nuance.
彼はぶつぶつ文句を言っていた。
He was muttering complaints.
Speaking in a low, grumbling voice to express dissatisfaction.
The go-to phrase for grumbling or muttering complaints under one's breath.
彼はいつもぶつぶつ言っている。
He's always muttering (complaints).
More direct: 'to complain'. Not necessarily muttered, but can be used with adverbs like 小声で (in a low voice).
彼は小声で不平を言った。
He muttered a complaint.
Colloquial verb for grumbling or complaining, often to someone else. Can be muttered or spoken.
Speaking in a low, unclear voice so that words are hard to catch.
Mumbling or muttering indistinctly, often with the mouth barely moving. Emphasizes unclear articulation.
彼はもごもごと何か言った。
He muttered something indistinctly.
To hesitate or mumble, often due to embarrassment or reluctance to speak clearly.
彼は口ごもりながら謝った。
He muttered an apology, stumbling over his words.
呟く is neutral and often used for thinking aloud or posting on social media (like tweeting). ぶつぶつ言う implies a continuous, low-pitched grumbling, often negative.
If the muttering is angry or resentful, ぶつぶつ言う or 不平を言う is more appropriate. 呟く can sound too soft.
He's always muttering complaints about work.