Formal:
* 不客气 (bù kè qì): This is the most common and polite way to say "you're welcome." It literally means "don't be polite," implying that you're not expecting anything in return.
* 没关系 (méi guān xì): This means "it doesn't matter" or "no problem," and is also appropriate in formal situations.
Informal:
* 不用谢 (bù yòng xiè): This means "no need to thank me" and is a more casual way to say "you're welcome."
* 没事 (méi shì): This means "nothing happened" or "it's okay," and is very informal.
Other options:
* 不用客气 (bù yòng kè qì): This combines the formality of "不客气" with the casual tone of "不用谢".
* 客气了 (kè qì le): This is more formal and implies that the other person is being too polite.
It's best to choose the appropriate phrase based on the context and your relationship with the person you're talking to.
For example, you would use "不客气" or "没关系" when talking to a stranger or someone in a formal setting. You would use "不用谢" or "没事" when talking to a friend or someone you know well.