pay的基本用法：
(1)pay (sb.) money for sth. 付錢（給某人）買……。例：I have to pay them 20 pounds for this room each month. 我每個月要付20英磅的房租。
(2)pay for sth. 付……的錢。例：I have to pay for the book lost.我不得不賠丟失的書款。
(3)pay for sb. 替某人付錢。例：Don?蒺t worry!I'll pay for you.別擔心，我會給你付錢的。
(4)pay sb. 付錢給某人。例：They pay us every month.他們每月給我們報酬。
(5)pay money back 還錢。例：May I borrow 12 yuan from you? I'll pay it back next week.你能借給我12塊錢嗎？下周還你。
(6)pay off one's money 還清錢。