自告奋勇

zì gào fèn yǒng

to volunteer

Character by character

自zì
self

告gào
announce

奋fèn
rouse

勇yǒng
courage

他自告奋勇去完成这个任务。

He volunteered to take on the task.

Tone: positive (praise).

Usually 自告奋勇地 + 去, 来 or 承担; praise for stepping forward.

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