but

but (liên từ) nghĩa là nhưng, tuy nhiên, mà, trái lại.

1. However, although, nevertheless, on the other hand (introducing a clause contrary to prior belief or in contrast with the preceding clause or sentence).Nhưng, tuy nhiên; dùng để mở đầu một mệnh đề trái với điều đã nghĩ hoặc tương phản với ý trước đó.
2. On the contrary, rather (as a regular adversative conjunction, introducing a word or clause in contrast or contradiction with the preceding negative clause or sentence).Mà, trái lại; dùng để đưa ra một từ hoặc mệnh đề đối lập với ý phủ định trước đó.
3. Used at the beginning of a sentence to express opposition to a remark.
4. Except that (introducing a subordinate clause which qualifies a negative statement); also, (archaic) with omission of the subject of the subordinate clause, acting as a negative relative, "except one that", "except such that".
5. Used to link an interjection to the following remark as an intensifier.

• She is very old but still attractive.
• She’s welcomed them but been rude to us.
• You told me I could do that, but she said that I could not.