Instead of just using 可是 or 但是, you can also use the softer and more informal 不过 (búguò). The meaning is closer to "however" or "nevertheless" in English in Chinese grammar.

Structure
Just like it's counterparts, "不过" is a conjunction that comes between two distinct clauses.

Examples

Wǒ xiǎnɡ bānɡ zhù nǐ, bú ɡuò wǒ méi yǒu kōnɡ.
我 想 帮助 你，不过 我 没有 空。
I want to help you, but I don't have time.