1. The boy whom sat beside him was his son. (whom→who)
2. He saw the kind faces of those which he loved. (which→whom)
3. There was only one house which was made of glass. (which→that)
4. Shy people often avoid situations who would make them embarrassed.
(who→which)
5. The reason that water becomes ice was a mystery to the little boy. (that→why)
6. I also have an offer to work at the law office that I worked last summer.
(that→where)
7. I still remember the day that I first met Jennifer. (that→when)
8. The police searched the house which the thief had stayed. (which→where)
9. I often think of the moment which I saw the UFO. (which→when)
10. Please pass me the book which cover is green. (which→whose)