Definition
This idiom is used to express that a helpful or kind act should be repaid with another act of kindness or assistance.
善意的行為應得到回報；以德報德。
I helped you move, so when you need something, I'll be happy to help.
我幫你搬家，所以當你需要什麼的時候，我會很樂意幫忙。
Since you lent me your notes last time, I'll help you study this time.
既然你上次借我筆記，這次我會幫你複習。
He took care of my cat last time, so I plan to give him a gift to show my thanks.
他上次照顧我的貓，所以我打算送他一份禮物表示感謝。