1. On the way home, we saw a lot of men, women and dogs which were playing in the park.

=> that (phần cụm danh từ gồm cả người lẫn vật => ko dùng which)

2. The man whom remained in the office was the manager.

=> who (whom dùng thay thế cho danh từ làm tân ngữ, mà câu này danh từ làm chủ ngữ)

3. This novel, which written by a well-known writer, should be read.

=> which is written (dạng bị động)

4. My friend George, that arrived late, was not permitted to enter the class.

=> who (sau dấu "," không dùng "that")

5. This is the only place which I can obtain scientific information.

=> where (= giới từ + which)

6. Chemistry is one branch of science on that most of the industries depend.

=> which (sau giới từ không dùng "that")

7. 1975 is the year in when the revolution took place.

=> bỏ "in" (đã dùng "when" (= in which) thì không dùng giới từ)

8. Mr. Brown, that teaches me English, is coming today.

=> who (sau dấu "," không dùng "that")

9. The hotel where we stayed in last year was excellent.

=> bỏ "in" (đã dùng trạng từ quan hệ "where" => không điền giới từ nữa)

10. At last they found the woman and her cat which were badly injured by the fire.

=> that (phần cụm danh từ gồm cả người lẫn vật => ko dùng which)

1. which -> that

2. whom -> who

3. written -> was written

4. that -> who

5. which -> where

6. that -> which

7. in -> bỏ

8. that -> who

9. in -> at

10. which -> that