The obligation rests with

You use this phrase to clarify who is in charge of a specific outcome. It usually follows the pattern: the obligation rests with + [Noun/Person]. You can use it to talk about legal duties or moral ones. It sounds very authoritative and serious. If you use it, people will think you are very confident. It is great for ending an argument about who should have done what. Just be careful not to sound too bossy with your friends!

Use this in professional meetings when defining project roles. It is perfect for legal discussions or academic debates. You can use it when talking about social issues too. For example, you might say the obligation to protect the environment rests with everyone. Use it when you want to sound sophisticated and precise. It works well in written reports or serious emails. It is also useful when you are tired of someone avoiding their duties.

Do not use this while ordering a pizza or at a casual party. Saying "the obligation rests with you to pass the chips" will make you sound like a robot. Avoid it in lighthearted texts with your partner. It is too heavy for small, everyday favors. If the situation is relaxed, just say "it is your turn" or "you should do it." Using C2-level English in a dive bar might get you some strange looks.

This phrase comes from the world of law and formal logic. In Western legal systems, we often talk about the "burden of proof." This is the idea that if you accuse someone, you must prove it. The phrase reflects a culture that values individual responsibility. It shows a desire for clear boundaries and rules. In English-speaking corporate culture, "owning" a task is a big deal. This phrase is the most formal way to say someone "owns" a problem.

• The onus rests with (even more formal)
• The responsibility lies with (very common)
• The burden falls on (sounds a bit more negative or heavy)
• The duty resides with (very old-fashioned or poetic)
• It is incumbent upon (extremely formal and slightly aggressive)