push against an open door

Verb

idiomatic

(idiomatic) To do something pointless or unnecessary; to try doing something already done.

Japanese Meaning

無駄な努力や、すでに達成されていることへの再挑戦など、効果が期待できない行動をすること / 意味のない、不要な行為を行うこと

If you keep trying to change his mind, you'll only push against an open door.

彼の考えを変えようと続けていても、ただ無駄なことをするだけだ。

Sense（1）

(idiomatic) To do something pointless or unnecessary; to try doing something already done.

pushes against an open door

（ present singular third-person ）

pushing against an open door

（ participle present ）

pushed against an open door

（ participle past ）

pushed against an open door

（ past ）