genou

In a sentence

• Il s'est blessé au genou en jouant au football.

  He injured his knee while playing football.

  Here, 'genou' refers directly to the anatomical part of the body, the knee.

• Elle s'est mise à genoux pour prier.

  She got down on her knees to pray.

  In this sentence, 'à genoux' describes the specific posture of being on one’s knees, indicating an action and a position.

• Le cheval plie parfois ses genoux avant de s'asseoir au sol.

  The horse sometimes bends its knees before sitting on the ground.

  This sentence uses 'genoux' to describe the joints on the horse’s legs corresponding to knees in humans, indicating a similarity in anatomy.