Translation guide
Expressing low, indistinct speech, often to oneself or in complaint.
mutter to oneself
mutter complaints
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.
He muttered to himself.
Literally 'to say a soliloquy'. A common phrase for talking to oneself, often used when the muttering is audible.
Muttering in a low, continuous, and often complaining manner. Slightly more negative nuance.
Speaking in a low, grumbling voice to express dissatisfaction.
The go-to phrase for grumbling or muttering complaints under one's breath.
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).
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.
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.
She often mutters to herself.
He was muttering complaints.
He muttered a complaint.
彼はいつも仕事の愚痴をこぼしている。
He's always muttering complaints about work.
He muttered an apology, stumbling over his words.