What is the origin of the idiom "hem and haw" and when to use it?

The origin of the idiom "hem and haw" is uncertain, but it is believed to have emerged from the sounds people make when they hesitate, pause, or try to gather their thoughts. The word "hem" represents the act of clearing one's throat or making a throaty sound, while "haw" imitates the sound of hesitation or uncertainty. It is a figurative expression that captures the verbal behavior of individuals who stammer, stumble, or speak evasively when faced with a question or decision.