Sam has just bought a new hat.
A new hat by Sam.

They made many plans at the party.
Many plans (by them) at the party.

George Orwell wrote some famous books.
Some famous books by George Orwell.

They are going to sell refreshments.
Refreshments (by them).

All people have left the town.
The town by all people.

Brutus and his friends killed Caesar.
Caesar by Brutus and his friends.

Joe has ruined Jill's doll.
Jill's doll by Joe.

Sam and his friends will probably play many games tomorrow.
Many games by Sam and his friends tomorrow.

Newton discovered the law of gravity.
The law of gravity by Newton.

They drank a lot of alcohol at the party.
A lot of alcohol (by them) at the party.

Sally and Mary are going to decorate the room.
The room by Sally and Molly.

Dolly wrote these letters last week.
These letters by Dolly last week.

Jill feeds the little dogs.
The little dogs by Jill.

The postman delivered this letter last week.
This letter (by the postman) last week.

Charles will visit Jack in NYC next year.
Jack by Charles in NYC next year.