Complex vs Compound Sentences

Using different structures improves the flow and pacing of your writing while keeping your readers engaged.

Two important sentence structures to know are complex sentences and compound sentences . So, what exactly is the difference between the two?

Read on to learn more about how to tell compound and complex sentences apart and how to use them in your writing effectively.

What Is a Compound Sentence?

A compound sentence includes multiple independent clauses that express equally significant ideas.

An independent clause is any clause that can be considered a complete sentence by itself. It needs to fulfill three criteria:

• Has a subject
• Has a verb
• Expresses a self-contained thought

For example, “I read a book” is an independent clause because it fulfills all three of the above criteria.

You can create a compound sentence by connecting multiple independent clauses with a conjunction, such as “and,” “or,” “but,” or “yet.”

Here are some compound sentences you could make with different conjunctions:

• I read a book, and my father went to the store.
• Susan has brown hair, but her sister has red hair.
• We can go for a walk, or we can stay at home.

You can also connect your independent clauses with a semicolon instead of a conjunction. For example, you could write:

• I read a book; my father went to the store.

When you’re constructing compound sentences, be careful to avoid comma splices, which is a common grammar mistake that occurs when you connect two independent clauses with only a comma. Instead, always use a conjunction with a comma, or use a semicolon instead of a comma.

You can use a grammar checker like ProWritingAid to look for instances of comma splices in your writing. ProWritingAid can help you make sure you’re using the right punctuation for your compound sentences.

Compound Sentence Examples

Let’s look at a few examples of compound sentences.

• I want cereal for breakfast, but there’s no milk in the fridge.
• She finished her homework, so now she can watch TV.
• He likes to run in the morning, and he also enjoys lifting weights.
• Sue can be rude at times, but she’s a nice girl most of the time.
• She was tired, so she went to bed early.
• He studied hard for the test, yet he failed to get a passing grade.
• We can go swimming at the pool, or we can go swimming in the ocean.
• She sings beautifully; she also plays the guitar.
• Gregg will travel by bus; he sold his car.
• The baby is tired, yet it refuses to fall asleep.

What Is a Complex Sentence?

Unlike compound sentences, which contain multiple independent clauses, complex sentences include only one independent clause, along with at least one dependent clause.

A dependent clause is any clause that can’t stand alone as a complete sentence. It either lacks a subject, lacks a verb, or fails to express a full thought.

For example, “while you were sleeping” is a dependent clause because it doesn’t express a standalone thought.

You can create a complex sentence by connecting a dependent clause to an independent sentence. You can connect them using a subordinating conjunction, such as “because,” “while,” “although,” “if,” “after,” “until,” “which” or “when.”

Only include a comma between the two clauses if the independent clause comes after the dependent clause. If the independent clause comes first, don’t include a comma.

• While you were sleeping, I went to the store.
• I went to the store while you were sleeping.

In this sentence, “I went to the store” is the independent clause, and “while you were sleeping” is the dependent clause. The subordinating conjunction “while” connects the two clauses.

Complex Sentence Examples

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