付钱(fù qián) - to pay, to hand over money in Mandarin

付钱 (fù qián) is the plain everyday way to say pay when no amount or recipient is named. English lets you say "did you pay?" with the object understood; Mandarin does not, so the generic object 钱 stays in place.

Because it is a verb-object pair, it splits when anything modifies it. 付了钱 for the completed action, 付一百块钱 with an amount, 付给他钱 with a recipient. Saying 付钱了一百块 is the classic learner mistake.

In a restaurant the natural request is 买单 or 结账, not 付钱. 付钱 describes the act of paying; 买单 asks for the bill so you can pay it. And 付款 (fù kuǎn) is the same idea in formal or written register, which is what you will see on a payment button online.