=> They called him a genius. 로 수정하셔요.
Did you found the money which you lost?
=> Did you find the money that you lost? 로 수정하셔요.
The potatoes I bought today isn't very fresh.
=> The potatoes I bought today aren't very fresh. 로 수정하셔요.
I went to the restaurant I read in the newspaper.
=> I went to the restaurant I read about in the newspaper. 로 수정하셔요.