Non-defining Relative Clauses มีลักษณะดังนี้

1. เป็น clause ที่เติมเข้ามาให้ข้อความชัดเจนขึ้นเท่านั้น ไม่มีความจำเป็นเป็นแก่ใจในประโยค

2. มีเครื่องหมาย comma คั่นข้างหน้า (และข้างหลัง clause)

3. จะใช้ that นำ clause ไม่ได้ ใช้เฉพาะ who , which , whom , whose เท่านั้น

เช่น Jim Smith , who lives next door , is coming to see you.

เมื่อกล่าวถึง Jim Smith ก็เป็นที่เข้าใจกันดีระหว่างผู้พูดและผู้ฟัง ดังนั้นข้อความ who lives next door จึงเพิ่มเข้ามาเพื่อให้รายละเอียดเท่านั้น My uncle John, who owns a department store , is very rich. Defining Non-defining Persons Things Persons Things Subject who (that) that (which) ...,who....., ......,which...., Object of the verb (whom) (which) ...,whom....., ......,which...., Object of preposition (whom)...prep (that, which)..prep ...,prep +whom....., ...,prep +which.., Possessive whose of which (or whose) .....,whose.., ....,of which.....,

1. Subject

1.1 Persons ใช้ who เท่านั้น

a) Charles Dickens was a very famous writer . He wrote "Oliver Twist". = Charles Dickens , who wrote "Oliver Twist" , was very famous writer.

b) Mr. John Brown received a reward. He got high marks in the final exam. = Mr. John Brown ,who got high marks in th final exam, recieved a reward.

c) My friend's uncle has gone to Paris. He works at the Ministry of Education. = My friend's uncle,who works at the Ministry of Education,has gone to Paris.

1.2 things ใช้ which เท่านั้น

a) Bangkok is very crowded. Bangkok is the capital of Thailand. = Bangkok , which is the capital of Thailand, is very crowded.

b) Chiang Mai is a fantastic city. It's in the north of Thailand. = Chiang Mai , which is in the North of Thailand, is a fantastic city.

c) I always read Thairath . It is a famous newspaper. = I always read Thairath , which is a famous newspaper.

2. Object of the verb

2.1 Persons ใช้ whom เท่านั้น และตัด object ในประโยคเดิม (ไม่สามารถละ whom ได้)

a) Peter Gray is coming to see you. I met him in Wellington. = Perter Gray , whom I met in Wellingon , is coming to see you.

b) Your girlfriend Jane came to see me. I really like her. = Youir girlfriend Jane , whom I really like , came to see me.

c) David and Martin have arrived. I mentioned them to you. = David and Martin , whom I mentioned to you , have arrived.

2.2 things ใช้ which เท่านั้น และตัด object ในประโยคเดิม (ไม่สามารถละ which ได้)

a) White elephants are rare. Thai people present them to the King. = White elephants , which Thai people present to the King , are rare.

b ) Thai rice isn't expensive. Most people like it. = Thai rice , which most people like , isn't expensive.

c) Dream World is famous for children. I visited Dream World last week. = Dream World , which I visited last week , is famous for children.

3. Object of the preposition

3.1 Persons

a) Tommayantee is a writer. You spoke to her yesterday. = Tommayantee , whom you spoke to yesterday , is a writer. = Tommayantee , to whom you spoke yesterday , is a writer.

b) Mr. Vinai is my teacher. You borrowed a pen from him. = Mr. Vinai , whom you borrowed a pen from , is my teacher. = Mr. Vinai , from whom you borrowed a pen , is my teacher.

3.2 Things

a) Thonburi is our former capital . We've just learnt about it. = Thonburi , which we've just learnt about , is our former capital. = Thonburi , about which we've just learnt , is our former capital.

b) The Oriental Hotel is very big. I stayed at it last night. = The Oriental Hotel , which I stayed at last night , is very big. = The Oriental Hotel , at which I stayed last night , is very big. (=The Oriental Hotel , where I stayed last night , is very big.) ( หมายถึงสถานที่ )

c) The White House is in Washington D.C.The President of America lives in it. = The White House , which the President lives in , is in Washington D.C. = The White House , in which the President lives, is in Washington D.C. (= The White House , where the President lives , is in Washington D.C.)

4. Possessive

4.1 Persons ใช้ whose เช่น

a) My eldest brother has just got married. You saw his girlfriend last Sunday. = My eldest brother , whose girlfriend you saw last Sunday , has just got married.

b) Krisana writes novels. Her picture was in the paper. = Krisana , whose picture was in the paper , writes novels.

4.2 Things ใช้ of which หรือ

a) My uncle's house is on Silom Road. The window of it is brown. = My uncle's house , of which the window is brown , is on Silom Road. (หรือ My uncle's house with the broken window is on Silom Road.)