531. Two Simple Sentences Make a Compound Sentence

When we put two simple sentences together, we form a compound sentence. We use a coordinating conjunction along with a comma to join two simple sentences. The word conjunction means “to join.”

There are seven coordinating conjunctions. If we list the coordination conjunctions in a certain order, they spell the word FANBOYS. Read down the left column of these words to see the word FANBOYS.
For
And
Nor
But
Or
Yet
So

In order to join two simple sentences into one sentence, we place a comma and one of the conjunctions between the two simple sentences. Look at these examples of how to join two simple sentences into a compound sentence:
We must go inside. The rain is starting.
We must go inside, for the rain is starting.
I bought strawberries. My mom bought ice cream.
I bought strawberries, and my mom bought ice cream.
Bob is old. Sarah is young.
Bob is old, but Sarah is young.
I had better bring an umbrella. We might get wet.
I had better bring an umbrella, or we might get wet.
I did not study. I got a good grade on the test.
I did not study, yet I got a good grade on the test.
The toy is broken. We should throw it away.
The toy is broken, so we should throw it away.

Use a comma and one of the FANBOYS conjunctions to join two simple sentences into a compound sentence.

▶Now it’s your turn. Use one of the FANBOYS conjunctions to join these two simple sentences into a compound sentence. Cheryl likes math. Joe likes science. Did you remember to use a comma just before the conjunction? Good for you!