grumble about 对...抱怨
grumble under one's breath 低声嘟囔
stop grumbling 停止抱怨
A: Why are you grumbling all the time?
A：你为什么一直在抱怨？
B: I just don't like the new rules.
B：我只是不喜欢新规定。
1) 抱怨
2) 咕哝
3) 发牢骚
1. 抱怨；咕哝
verb
1. to complain in a low, unhappy voice
Synonym: mutter, murmur, moan