If you want to treat your friends, you can say? Nǐ lái mǎidān bɑ.你来买单吧。|Nǐ;qǐnɡ kè;bɑ.你 请客 吧。|Wǒ qǐnɡ kè.我 请 客。|Zánmen AA zhì bɑ.;咱们 AA;制吧。