Here are two simple sentences: I play the piano. Jenna plays the trumpet.
We can make these two simple sentences into a compound sentence by adding a comma and the conjunction and: I play the piano, and Jenna plays the trumpet.
It is important to know that a compound sentence has two complete thoughts joined together. Each complete thought has a subject and a verb. Only use a comma when joining two complete thoughts.
Notice how each of these sentences has a subject and a verb on each side of the word and.
I drove to school, and my sister walked.
Jim has a German shepherd, and Mary has a dachshund.
Sometimes we automatically use a comma in a sentence with and, but we only need a comma if there is a complete thought on each side of the and. Be sure that each complete thought has a subject and a verb.
I bought a new bike and went for a ride.
This sentence has the word and in the middle. But look at both sides of the word and.
The one side has a complete thought: I bought a new bike.
The other side of the word and is not a complete thought: went for a ride.
Do not put a comma into a sentence with and unless there is a complete thought on each side of the and.
Only put a comma after the word and when there is a complete thought on each side of and.
▶It’s your turn. Which of these two sentences needs a comma after the word and? John plays basketball and Sarah plays tennis. John plays basketball in the winter and runs track in the spring. Did you figure out that the first sentence has two complete thoughts? Good for you.