acting as someone’s stand-in
主将の入院中は私が代理を務めた。
I served as captain while the regular captain was hospitalized.
彼は父親の代理をした。
He acted as a proxy for his father.
私が彼の代理をします。
I’ll act on his behalf.
首相の留守中は外務大臣が代理を務める。
The foreign minister will serve as acting prime minister while the prime minister is away.
留守の間私の代理をしていただけますか。
Could you act on my behalf while I’m away?
キャプテンの入院中は、私が代理を務めた。
I filled in for the captain while he was in the hospital.
私が父の代理をするつもりだ。
I intend to act as my father’s representative.