go through the motions

US /ɡoʊ θruː ðə ˈmoʊʃənz/
UK /ɡoʊ θruː ðə ˈmoʊʃənz/
"go through the motions" picture
1.

形だけこなす, 義務的に行う

to do something in a mechanical or unenthusiastic way, without genuine interest or effort

:
He was just going through the motions at work after he decided to quit.
彼は辞職を決めてから、仕事でただ形だけこなしていた
She felt like she was just going through the motions in her relationship.
彼女は自分の関係でただ形だけこなしているように感じていた。