A compound sentence is formed by joining two simple sentences together. Each independent clause is a simple sentence, We join the two simple sentences with a comma and a coordinating conjunction.
There are seven coordinating conjunctions: for, and, nor, but, or, yet, so
We sometimes call these coordinating conjunctions the FANBOYS because their first letters spell out that word.
Whenever you connect the two independent clauses (or the two simple sentences), you need to use a comma with one of the FANBOYS.
Look at these examples:
Bob is a doctor. Mary is a nurse.
Bob is a doctor, and Mary is a nurse.
It is raining. I will take an umbrella.
It is raining, so I will take an umbrella.
It is sunny. It is also cold.
It is sunny, yet it is also cold.
Should we go to a movie? Should we go out for ice cream?
Should we go to a movie, or should we go out for ice cream?
I like to play card games. Jim likes to play video games.
I like to play card games, but Jim likes to play video games.
Each time we join two simple sentences into one compound sentence, we must use a comma and one of the coordinating conjunctions.
▶Now you try it. Use one of the FANBOYS to join these two simple sentences: We got snow today. I will shovel the driveway. Did you make these two sentences into one compound sentence? Did you put a comma before the conjunction when you joined the two sentences? Good for you!