arrodillar

To make someone kneel, though it's overwhelmingly used in its reflexive form, arrodillarse, for kneeling oneself — in prayer, in front of a religious statue, when proposing marriage, or when forced into submission. The reflexive is far more common than the plain transitive in real speech.

• Se arrodilló para pedirle matrimonio. — He knelt down to propose to her.
• Los fieles se arrodillaron ante el altar. — The worshippers knelt before the altar.
• Lo arrodillaron a la fuerza frente a la multitud. — They forced him to his knees in front of the crowd.

Forgetting the reflexive pronoun for kneeling oneself — arrodilló (someone else) versus se arrodilló (himself); dropping the se is a common slip when translating directly from English "he knelt."