please help me!

[nguyen emanuen]

mong anh chị giải thich cho em khi nào bỏ dấu

phẩy , khi nào không ? nếu có thiếu dấu thi bỏ

vào dùm em, xin anh chị giải thích các cặp a và b cho em hiểu nó khác nhau như thế nào? . thank you very much
1 the S.S. Titan is a supertanker. it crashed into a cargo ship

1a) the S.S. titan which is a suppertanker crashed into a cargo ship

B )Tom's father goes swimming everyday . Tom's father is 78

Tom's father who is 78 goes swimming everyday

2a)Ms . Laine lost her house. she is sleeping in a hotel

Ms . laine who lost her is sleeping in a hotel

B)the clock was Mary's . it stopped running

the clock which stopped running was mary's

3a) the temperature will be low today. it will rise tomorrow

the temperature which will be low today will rise tomorrow

B) people drink a lot of tea. they live in vietnam

people who live in vietnam drink alot of tea

4a) the house was on the edge of a cliff . it fell into the ocean

the house which was on the edge of a cliff fell into the ocean

B) she showed me a photograph of her son .her son is a policeman

she showed me a photograph of her son who is a policeman

5a ) the van belonged to the sandiego zoo. It contained two boxes of snakes

the van which belonged to the sandiego zoo contained two boxes of snakes

B ) the new stadium will be opened next month . the stadium holds 90.000 people

the new stadium which holds 90.000 will be opened next month

6a) the local residents are spending the night in a school . they are afraid to go home

the local who are resident are spending the night in a school are afraid to go home

B) the population of HCM city is more inbcreasing . HCM city is the largest city in Vietnam

the population of HCM city which is the largest city in Vietnam is more in creasing

7 )john is one of my closest friend . I have known john for eight years

john who I have known for eight years is one of my closest friend

8) the rice is very good . it grows in vietnam

the rice which grows in vietnam is very good

9) the postman was late this morning . the postman is nearly always on time

the postman who is nearly always on time was late this morning

10) a city has many problems . it grows very rapidly

a city which grows very rapidly has many problems

[english-learner]

mong anh chị giải thich cho em khi nào bỏ dấu

phẩy , khi nào không ? nếu có thiếu dấu thi bỏ

vào dùm em, xin anh chị giải thích các cặp a và b cho em hiểu nó khác nhau như thế nào? . thank you very much
1 the S.S. Titan is a supertanker. it crashed into a cargo ship

1a) the S.S. titan which is a suppertanker crashed into a cargo ship

B )Tom's father goes swimming everyday . Tom's father is 78

Tom's father who is 78 goes swimming everyday

2a)Ms . Laine lost her house. she is sleeping in a hotel

Ms . laine who lost her is sleeping in a hotel

B)the clock was Mary's . it stopped running

the clock which stopped running was mary's

3a) the temperature will be low today. it will rise tomorrow

the temperature which will be low today will rise tomorrow

B) people drink a lot of tea. they live in vietnam

people who live in vietnam drink alot of tea

4a) the house was on the edge of a cliff . it fell into the ocean

the house which was on the edge of a cliff fell into the ocean

B) she showed me a photograph of her son .her son is a policeman

she showed me a photograph of her son who is a policeman

5a ) the van belonged to the sandiego zoo. It contained two boxes of snakes

the van which belonged to the sandiego zoo contained two boxes of snakes

B ) the new stadium will be opened next month . the stadium holds 90.000 people

the new stadium which holds 90.000 will be opened next month

6a) the local residents are spending the night in a school . they are afraid to go home

the local who are resident are spending the night in a school are afraid to go home

B) the population of HCM city is more inbcreasing . HCM city is the largest city in Vietnam

the population of HCM city which is the largest city in Vietnam is more in creasing

7 )john is one of my closest friend . I have known john for eight years

john who I have known for eight years is one of my closest friend

8) the rice is very good . it grows in vietnam

the rice which grows in vietnam is very good

9) the postman was late this morning . the postman is nearly always on time

the postman who is nearly always on time was late this morning

10) a city has many problems . it grows very rapidly

a city which grows very rapidly has many problems

Bạn cần nắm vững nguyên tắc như sau:
Ta dùng dấu phẩy khi relative pronoun là một mệnh đề thêm thông tin vào chứ không đóng vai trò quan trọng (không có nó phần còn lại vẫn [b]rõ nghĩa[b].
Ta không dùng dấu phẩy khi relative pronoun là một phần cần thiết của cả câu nếu không có nó thì câu nói nghĩa sẽ mông lung mơ hồ. Theo đó thì câu

Tom's father who is 78 goes swimming everyday
Nên có dấu phẩy. Bởi rõ ràng Tom chỉ có 1 ông cha Cái chuyện 78 tuổi chỉ là phụ thêm vào thôi

Còn câu cuối này.

a city which grows very rapidly has many problems
Câu này rõ ràng không cần dấu phẩy vì which grows very rapidly là một phần không thể thiếu của câu để cho biết loại thành phố gì.

Tôi lấy thí dụ thêm :

My sister who is 38 will go to Alaska next week : Câu này không có dấu phẩy vì tôi có 2 chị gái nên phải nói rõ là chị nào.
Trường hợp tôi đã giới thiệu trước đó tôi chỉ có một chị (hay em gái) thì lại phải có dấu phẩy.

Bạn đã hiểu thì có thể tự làm các câu còn lại và cả trăm câu nữa.

[nguyen emanuen]

thank you for you help . thank you very much