What is a compound sentence? — Simple explanation for a 10-year-old

What is a compound sentence?

A compound sentence joins two complete thoughts (called independent clauses) into one sentence. Each independent clause can stand alone as its own sentence.

Step-by-step

1. Find the two complete thoughts. Each one must have a subject (who or what) and a verb (action or being).
2. Choose a joining word. Use a coordinating conjunction like those in FANBOYS: for, and, nor, but, or, yet, so.
3. Use punctuation correctly. Put a comma before the conjunction when it joins two independent clauses. Or you can join them with a semicolon without a conjunction.

Examples

• Simple sentences: I wanted to play. It started to rain.
• Compound sentence: I wanted to play, but it started to rain. (Two independent clauses joined by but + comma)
• Another example: Maria studied for the test, so she did well. (Maria studied for the test.) + (She did well.)
• Using a semicolon: The sun was setting; the sky turned orange. (No conjunction needed when you use a semicolon.)

Common mistake

Don't make a run-on by joining two complete sentences without a comma and conjunction or without a semicolon. Wrong: I wanted to play it started to rain. Right: I wanted to play, but it started to rain.

Quick rules to remember

• Two complete sentences = two independent clauses.
• Use a comma + a FANBOYS conjunction to join them.
• Or use a semicolon to join them without a conjunction.

Try these (practice)

1. Join: The dog barked. The cat ran away. (use but)
2. Join: Sam finished his homework. He watched a movie. (use so)
3. Decide if this is a compound sentence: I ate my lunch and I read a book.

Answers

1. The dog barked, but the cat ran away.
2. Sam finished his homework, so he watched a movie.
3. Yes, it is a compound sentence. It has two complete thoughts joined by and: (I ate my lunch.) + (I read a book.)

If you want, I can give you more practice problems or a short worksheet to try!