Compound-Complex Sentence: Definition and Examples

One way to add variety to your writing is to play with sentence structures. There are four main types of sentence structures: simple, compound, complex, and compound-complex.

Today, we’re looking at compound-complex sentences. These are the most complicated sentence structures, but when done properly they can improve the flow of your writing.

Read on to learn more about what compound-complex sentences are and how to write them.

What Is a Compound-Complex Sentence?

A compound-complex sentence combines a compound and a complex sentence.

A compound sentence contains two or more independent clauses. A complex sentence has one independent clause combined with one or more dependent clauses.

Therefore, a compound-complex sentence has two or more independent clauses and at least one dependent clause.

Compound-complex sentences are typically the longest of all sentences. Compound-complex sentences allow you to add a layer of complexity to your writing. They improve the flow and keep your readers engaged. They’re also useful if you’re explaining complicated ideas.

Let’s look at an example of a compound-complex sentence below:

• Though Jack prefers watching comedy films, he rented the latest spy thriller, and he enjoyed it very much.

In the sentence above there are two independent clauses, “he rented the latest spy thriller,” and “he enjoyed it very much.” The dependent clause is “Though Jack prefers watching comedy films.” The two independent clauses are joined by the coordinating conjunction “and.”

How to Write a Compound-Complex Sentence

Here are four simple steps for how to write effective compound-complex sentences.

• Choose your independent clauses: Independent clauses can stand on their own as complete sentences because they have both a subject and a verb. A compound-complex sentence should have at least two independent clauses that are related in some way.
• Choose your dependent clause: Unlike independent clauses, dependent clauses aren’t complete sentences because they do not express complete thoughts. The dependent clause should relate to the independent clauses, which means they must provide additional information.
• Add your conjunctions: There are two types of conjunctions: subordinating conjunctions and coordinating conjunctions. Coordinating conjunctions join independent clauses while subordinating conjunctions introduce dependent clauses.
• Punctuate your sentence properly: Compound-complex sentences are longer than other sentence structures. so you’re more likely to have run-on sentences. Run-on sentences happen when two independent clauses are connected by only a comma. You should either switch the comma to a semi-colon or use the comma together with a conjunction.

Troubleshooting

Comma splices are a common mistake to make when writing compound-complex sentences. Use a grammar checker, such as ProWritingAid, to identify any instances of comma splices, so you can fix them and make your sentences stronger.

Compound-Complex Sentence Structures

The easiest way to understand the structure of a compound-complex sentence is to first understand the structures of compound and complex sentences.

A compound sentence combines two or more independent clauses. Independent clauses are complete sentences.

Let’s look at an example of a compound sentence:

• There’s an oak tree behind my house, and I go there sometimes when I’m lonely.

The sentence above has two independent clauses, “there’s an oak tree behind my house,” and “I go there sometimes when I’m lonely.”

The independent clauses in a compound sentence are typically joined by a coordinating conjunction. In the sentence above, the independent clauses are joined by the conjunction “and.” The other six coordinating conjunctions that can be used are “for,” “or,” “nor,” “but,” “yet,” and “so.”

Compound sentences can also be joined by semicolons instead of a coordinating conjunction and a comma. For example, the same sentence above can be written like this:

• There’s an oak tree behind my house; I go there sometimes when I’m lonely.

A complex sentence has an independent clause and at least one dependent clause. For example:

• There’s an oak tree behind my house, which my brother and I used to climb when we were kids.

In the sentence above there’s an independent clause, “there’s an oak tree behind my house” and a dependent clause, “which my brother and I used to climb when we were kids.”

In complex sentences, dependent clauses are introduced by subordinate conjunctions. In the sentence above, we used “which.” Other subordinate conjunctions include “after,” “although,” “if,” “until,” and “while.”

A compound-complex sentence combines the structure of a compound sentence and a complex sentence. Here is an example of a compound-complex sentence:

• There’s an oak tree behind my house, which my brother and I used to climb when we were kids, and I go there sometimes when I’m lonely.

This sentence includes two independent clauses and one dependent clause.

Let’s break down the sentence to highlight all the relevant sections of the sentence:

• Independent clause 1: There’s an oak tree behind my house
• Subordinating conjunction: which
• Dependent clause: my brother and I used to climb when we were kids
• Coordinating conjunction: and
• Independent clause 2: I go there sometimes when I’m lonely.

Compound-Complex Sentence Examples

Compound-complex sentences are very useful in analytical and academic writing for explaining complicated topics. However, they can also be used in creative writing where you want to spice up your writing to keep your readers engaged.

Here are a few more examples of compound-complex sentences:

• She completed her literature review, but she still needs to work on her methods section even though she finished her methods course last semester.
• While waiting for the paint to dry, Angela went to Home Depot, and Martin organized the kitchen appliances.
• After a long time, I still don’t understand her reason for leaving, but I guess it’s for the best.
• Sam and Alex only knew each other for a year, but they decided to get married before Sam went abroad, and that was the best decision they ever made.
• As I put my coat on, I looked out the window, but I couldn’t see any rain.
• While Tom reads novels, Jack reads comics, but Sam only reads magazines.

Conclusion on the Compound-Complex Sentence

Remember, a compound-complex sentence combines a compound and complex sentence. These sentences have at least two independent clauses and a dependent clause.

Now you’re well on your way to using compound-complex sentences in your own writing. Play around with your sentence structures, so your writing doesn’t become monotonous.

Use a variety of sentence types and use ProWritingAid’s sentence structure report to show you where your sentences could use a little more attention.

Have you tried  ProWritingAid  yet? What are you waiting for? It’s the best tool for making sure your copy is strong, clear, and error-free!