Murmurar vs. resmungar
While both murmurar and resmungar describe speaking in a low, indistinct voice, the main distinction lies in the intent and emotion of the speaker. Murmurar refers to the volume and softness of the voice, often associated with secrets or gentleness, while resmungar is specifically used to describe grumbling or complaining with a bad attitude.
Murmurar
B2The verb murmurar means to speak very softly, indistinguishably, or in a whisper. It is often used for sharing secrets, speaking romantically, praying quietly, or gossiping without being overheard. It focuses on the low volume rather than the mood.
Ele inclinou-se e murmurou um segredo ao ouvido dela.
(He leaned in and murmured a secret in her ear.)
A audiência começou a murmurar quando o anúncio foi feito.
(The audience began to murmur when the announcement was made.)
Ela murmurou uma oração silenciosa antes de entrar no avião.
(She murmured a silent prayer before getting on the plane.)
O aluno tímido apenas murmurou a resposta correta.
(The shy student only murmured the correct answer.)
Resmungar
B2The verb resmungar means to mutter or grumble, specifically with a tone of annoyance, dissatisfaction, or anger. It describes speaking unclearly because the person is in a bad mood or complaining under their breath.
O meu avô costuma resmungar quando vê as notícias na televisão.
(My grandfather usually grumbles when he watches the news on TV.)
O adolescente saiu da sala a resmungar porque não queria lavar a loiça.
(The teenager left the room grumbling because he didn't want to wash the dishes.)
Não vale a pena resmungar sobre o tempo se não podes mudá-lo.
(It is not worth grumbling about the weather if you cannot change it.)
O cliente começou a resmungar sobre o preço alto do café.
(The customer started muttering about the high price of the coffee.)
Summary
In short, use murmurar when the sound is soft, whispery, or secretive (similar to to murmur). Use resmungar when the sound implies complaining, being grumpy, or expressing annoyance under one's breath (sImilar to to grumble or to grouse).