Jawaban:

1. I answered five telephone calls today. All were from Japan.
   => I answered five telephone calls that/which were from Japan today.
2. I am working on my project. It is supposed to be finished in June.
   => I am working on my project, which is supposed to be finished in June.
3. What's happened to the man? He looks awful.
   => What's happened to the man who looks awful?
4. I went out with the man. His car is new.
   => I went out with the man whose car is new.
5. I hate the people. They like to badmouth others.
   => I hate the people who like to badmouth others.
6. Have you found your wallet? You lost it.
   => Have you found your wallet that you lost?
7. He is the writer. His book is a best seller.
   => He is the writer whose book is a best seller.
8. They are the people. They like to hear themselves speak.
   => They are the people who like to hear themselves speak.
9. He thanked all the people. He loved them.
   => He thanked all the people whom he loved.
10. Nani likes to teach English. She considers it a beautiful language.
    => Nani, who considers it a beautiful language, likes to teach English.
11. I was telling you the truth. Nobody believed it.​
    => I was telling you the truth that nobody believed.

Penjelasan:

Dalam adjective clausedigunakanrelative pronoun. Ada beberapa relative pronoun. Berikut adalah perbedaan penggunaan dari masing-masing relative pronoun:

1. "That"
   Relative pronoun "that" digunakan untuk merujuk pada orangataubendadalamadjective clause yang berfungsi sebagai objek, baik itu objek langsung maupun tidak langsung. Contohnya:
   1) The book that I bought yesterday was expensive.
   (Objek: book)
   2) The girl that I saw at the party is my friend.
   (Objek: girl)
2. "Which"
   Relative pronoun "which" digunakan untuk merujuk pada bendadalamadjective clause.
   Contoh:
   1) The car, which is parked outside, is mine.
   (Objek: car)
   2) The book, which I read yesterday, was interesting.
   (Objek: book)
3. "Who"
   Relative pronoun "who" digunakan untuk merujuk pada orangdalamadjective clause yang berfungsi sebagai subjek. Contohnya:
   1) The woman who is talking to John is his mother.
   (Subjek: woman)
   2) The boy who won the competition is very talented.
   (Subjek: boy)
4. "Whose"
   Relative pronoun "whose" digunakan untuk menunjukkan kepemilikanataukepunyaan, dan biasanya digunakan untuk merujuk pada orang atau benda dalam adjective clause.
   Contoh:
   1) The man whose car was stolen reported it to the police.
   (Kepemilikan: car, pemilik: the man)
   2) The student whose grades are excellent will receive a scholarship.
   (Kepemilikan: grades, pemilik: the student)
5. "Whom"
   Relative pronoun "whom" digunakan untuk merujuk pada orang dalam adjective clause yang berfungsi sebagai objek langsung atau tidak langsung. Contohnya:
   1) The woman whom I met yesterday is a doctor.
   (Objek langsung: woman)
   2) The boy whom the teacher was talking to is my brother.
   (Objek tidak langsung: boy)