behaves
Il se comporte mal avec ses collègues.
He behaves badly towards his colleagues.
Il se comporte de façon bizarre.
He is acting strangely.
Parfois, il se comporte bizarrement.
Sometimes he behaves strangely.
Il se comporte bizarrement ces derniers temps.
He's been acting strange lately.
Comment il se comporte avec vos parents ?
How does he behave with your parents?
— La petite Véra (1988)
Il se comporte plutôt bizarrement ces derniers temps.
He’s been acting rather strangely lately.
Il se comporte en vedette du rock.
He acts like a rock star.
Il se comporte comme s'il était quelqu'un.
He acts as if he were somebody.
He behaves very well.