expression, ichidan verb
know one's place; understand one's position
Used when someone behaves appropriately according to their social standing, role, or situation. Often implies humility or restraint.
彼は分をわきまえて、上司の前では控えめに振る舞った。
He knew his place and behaved modestly in front of his boss.
分をわきまえずに
Don't say cheeky things without knowing your place.