付(fù) - to pay, to hand over in Mandarin

付 (fù) is the plain verb for paying money over. In speech you will hear it most often as 付钱 (pay), 付款 (make a payment) and 付不起 (cannot afford), and in restaurants the fight over the bill is settled with 我来付.

It also carries the wider sense of handing something across, which is where 交付 (to deliver) and 付出 (to give up, to expend) come from. 付出 is worth learning early: 他为这个家付出了很多 means he gave a great deal for this family, with no money involved at all.

English speakers often confuse 付 with 给. 给 is give to a person; 付 is settle what is owed. You 给他一本书 but you 付房租. Using 给 for the rent sounds like you are making the landlord a present.