sit in for

idiomatic

(idiomatic) To substitute; to take somebody's place.

Japanese Meaning

（誰かの）代役を務める / （誰かの）代理を務める / （誰かの）代わりにその役割を引き継ぐ

Could you sit in for me at the staff meeting tomorrow?

明日のスタッフ会議で私の代わりを務めてもらえますか？

Sense（1）

(idiomatic) To substitute; to take somebody's place.

Can you sit in for him while he's gone?

sits in for

（ present singular third-person ）

sitting in for

（ participle present ）

sat in for

（ participle past ）

sat in for

（ past ）