All he ever does is grumble about things.

他只会抱怨。

《牛津词典》

They grumble about how hard they have to work.

他们抱怨自己工作得很辛苦。

《柯林斯英汉双解大词典》

They will grumble about having to do the work.

他们将为不得不干那项工作而抱怨。

youdao

Frequent fliers may grumble about increased ticket prices, extra baggage fees, schedule changes and discontinued routes.

FORBES: The Results Are In, And Airline Revenues Are Growing

Regulars in one village pub grumble about immigrants (of whom, locally, there are almost none).

ECONOMIST: Marginal seats

Businessmen, for instance, grumble about the bribes their lorry-drivers have to pay to highwaymen in uniform.

ECONOMIST: A struggle to keep the good times rolling