EF2/3 Compound sentences

1. Jim cut the grass, and Ed weeded the garden.
Jim cut the grass, but Ed weeded the garden.

Jim cut the grass, so Ed weeded the garden.

SLIGHTLY DIFFERENT PURPOSE, INTENTION

2. I was very tired last night, so I went to bed early.

I went to bed early last night, for I was very tired. 
I went to bed early last night because I was very tired. COMPLEX

5. Mr. Smith earns a lot of money, so he never saves any.
Mr. Smith earns a lot of money, but he never saves any.

6. Jack needs a new jacket. He lost his leather one.
Jack needs a new jacket, for he lost his leather one.
He Jack lost his leather one jacket, so Jack he needs a new jacket one. 

8. I will be late for my appointment, so we have to leave in 10 minutes.
We have to leave in 10 minutes, or I will be late for my appointment.