paid 是 pay 的过去式、过去分词

pay

KK [pe] /peɪ/

动词

1
支付、付钱、缴
I paid the restaurant bill with my credit card.
我用信用卡支付了餐厅的帐单。
2
给薪、支付报酬
The company pays its engineers well above average.
这家公司给工程师的薪水远高于平均水准。
3
划算、值得常用 it pays to
It pays to read the whole contract before signing.
签约前把整份合约看完是值得的。
4
获利、赚钱
The small bookstore has never really paid.
这家小书店其实从来没有赚过钱。
5
付出代价、遭到报应常接 for
He will pay for lying to his closest friends.
他对最要好的朋友说谎，总会付出代价。
6
给予、表示用于固定搭配
Please pay attention to the safety instructions.
请注意这些安全指示。

1
还清、付清pay off
They finally paid off the loan on their apartment.
他们终于把房子的贷款还清了。
2
奏效、有回报pay off
All those late nights of studying finally paid off.
那些熬夜读书的日子终于有了回报。
3
偿还、还钱pay back
I'll pay you back as soon as I get my salary.
我一领到薪水就把钱还你。