1. The man who is talking to John is from Korea.

⇒ The man talking to John is from Korea.

(Động từ ở thể chủ động → present participle)

who is talking → talking

2. The ideas which are presented in that book are interesting.

⇒ The ideas presented in that book are interesting.

(Động từ ở thể bị động → past participle)

which are presented → presented

3. John Quincy Adams, who was born on July 11th 1767, was the sixth president of the United States.

⇒ John Quincy Adams born on July 11th 1767 was the sixth president of the United States.

(Động từ ở thể bị động → past participle)

4. These are the ancient houses which were built a long time ago.

⇒ These are the ancient houses built a long time ago.

(Động từ ở thể bị động → past participle)