What is the difference between "must" and "have to" in terms of obligation?

The distinction between "must" and "have to" in expressing obligation centers on the source of that obligation. "Must" typically conveys an internal obligation or a personal imperative, reflecting the speaker's judgment, desire, or a strong belief about a certain action. For example, if someone says, "I must exercise more," they are expressing a personal commitment or a value they believe in.

On the other hand, "have to" usually denotes an external obligation imposed by circumstances or rules, suggesting that the speaker does not necessarily agree with it but must comply due to outside factors. For instance, saying "I have to submit the report by Monday" indicates that there is a requirement or a deadline set by someone else or some situation, which necessitates the action.

This nuanced difference captures how individuals perceive and communicate about their responsibilities and obligations, facilitating a more precise understanding of their motivations and the context of their statements regarding necessity.