1 He is very sociable, so he has many friends.

He has many friends

2. Today is Sunday, so I don't have to go to work.

Because

3. She's very helpful, so we like her.

Since

4. He was tired, so he stopped working.

Because

5. He was tired, so he went to bed early.

Because he

6. I'm very busy today, that's why I can't go fishing with you.

I can't go fishing with you today

`Answer :` 

`1.` He has many friends because he is very sociable.

`2.` Because today is Sunday, I don't have to go to work.

`3.` Since she's very helpful, we like her.

`4.` Becausehe was tired, he stopped working.

`5.` Because he was tired, he went to bed early.

`6.` I can't go fishing with you today because I'm very busy.

 $----------------------$

`@` Form :

`-` S `+` V `+` O, so `+` S `+` V `+` O.

`->` So là từ nối dùng để nối hai mệnh đề độc lập, biểu thị kết quả của mệnh đề trước đó.

`=>` Because `+` S `+` V `+` O, S `+` V `+` O.

`->` Because là từ nối dùng để nối hai mệnh đề, biểu thị nguyên nhân của mệnh đề sau đó.

`=>` Since `+` S `+` V `+` O, S `+` V `+` O.

`->` Since là từ nối dùng để nối hai mệnh đề, biểu thị lý do của mệnh đề sau đó