We can combine two simple sentences into a compound sentence using a comma and one of the FANBOYS conjunctions. We can also make two simple sentences into a compound sentence using a semicolon. Look at these examples:
Today is Thursday. We have basketball practice.
Today is Thursday, so we have basketball practice.
Today is Thursday; we have basketball practice.
I baked a cake. We can eat it tonight.
I baked a cake, and we can eat it tonight.
I baked a cake; we can eat it tonight.
A semicolon (:) works just like a comma and conjunction by joining two simple sentences into a compound sentence.
▶It’s your turn. Change this compound sentence into a sentence with a semicolon. It is raining, so our game is cancelled. Did you use a semicolon in place of the comma so? Good for you!