l'en empêcher

prevent him/her from doing it

→ le
phrase Rare #22,079
prevent him/her from doing it Used when referring back to an action already understood from context. The object pronoun usually refers to a person, and "en" refers to the action or thing they would do.
FR: Je vais l'en empêcher si c'est possible.
EN: I'm going to prevent him from doing it if possible.

Je resterai éveillé pour l'en empêcher.

I will stay awake to prevent him.

Je dois l'en empêcher.

I have to stop him.

Tu n'aurais rien pu faire pour l'en empêcher.

There was nothing you could have done to stop it.

— Tár (2022)

Mais l'en empêcher est inutile.

But there's no point in trying to stop them.

— Perfetti sconosciuti (2016)

J'ai voulu l'en empêcher.

I wanted to stop him.

Qui sommes nous pour l'en empêcher.

Who are we to stop him?

— Ratatouille (2007)

Il faut l'en empêcher.

We must stop him.

J'aurais dû l'en empêcher.

I should have stopped him.

Tu dois l'en empêcher.

You have to stop him.

Mais comment l'en empêcher?

But how can we stop him?

— Henry V (1989)