Compound-Complex Sentence: What Is a Compound-Complex Sentence? Definition and Examples

By Carly Forsaith, updated on June 21, 2023

Would you like to learn what a compound-complex sentence is? If so, you've come to the right place. This article will teach you what you need to know to understand and use them in your writing.

In short:

  • A compound-complex sentence comprises at least two independent clauses and at least one dependent clause. 

This guide is part of our free online Grammar Book.

Sentence Structure Types

Let's begin by discussing the different types of sentence structure in English grammar. Compound-complex sentences are just one of four types.

But first of all, let's clarify what a sentence is. It's a group of words that comes together to form a thought. At the very least, a sentence must contain one independent clause. But often, they have more than one, and sometimes they even combine independent clauses with dependent clauses.

The other thing you should know about sentences is that they always have at least one subject (the person or thing doing the action of the verb) and one predicate (describes the verb's action). Even the most basic of sentences will have both of these things (the only exception is an imperative sentence where the subject is not mentioned).

The four types of sentence structure are:

  • Simple sentence: a single independent clause.
  • Compound sentence: two or more independent clauses joined together.
  • Complex sentence: an independent clause and at least one dependent clause.
  • Compound-complex sentence: two or more independent clauses and at least one dependent clause.

What Is a Compound-Complex Sentence?

Suppose you know that a compound sentence is two or more independent clauses, and a complex sentence is an independent clause and one or more dependent clauses. In that case, you can easily deduct what a compound-complex sentence is. That's right; it's a sentence that combines at least two independent clauses and at least one dependent clause.

I know that sounds a little complicated, so let's look at an example and pull it apart.

My mom told me that she wants to find a new job, but she doesn't know where to start.

"My mom told me that" is our dependent clause. That's right: it doesn't convey a complete thought, so it can't stand alone. That makes it a dependent clause.

"She wants to find a new job" is our independent clause #1. It conveys a complete thought and can stand alone. The same can be said for "she doesn't know where to start," which is our independent clause #2.

"But" is the coordinating conjunction that connects the two independent clauses, as is required in any compound sentence, which brings us to my next point.

How to Make a Compound-Complex Sentence

To make the perfect compound-complex sentence, you need:

  • at least two independent clauses
  • at least one dependent clause
  • conjunctions
  • good punctuation

The first and second points are pretty self-explanatory: you need clauses to make a sentence.

In terms of conjunctions, there are two types:

  • subordinating, which connects dependent clauses
  • coordinating, which connects dependent clauses to independent clauses.

Connecting Your Clauses with Conjunctions

You'll often see subordinating conjunctions in complex and compound-complex sentences because they're helpful for joining a dependent clause to an independent clause.

Here's a list of common ones:

  • after
  • although
  • before
  • even if
  • because
  • whenever
  • so that

We say they connect clauses because they show the relationship between them.

Take the following sentence, where the conjunction 'because' explains the cause-and-effect relationship between the two clauses:

You can't go on the ride because you're too short. 

Coordinating conjunctions, on the other hand, connect dependent and independent clauses.

There are seven, which you can remember thanks to the popular acronym FANBOYS:

  • for
  • and
  • nor
  • but
  • or
  • yet
  • so

They tend to show the relationship between parts of speech in the two clauses.

In the following sentence, the conjunction 'or' shows the relationship between the two verbs 'take' and 'look' by indicating a choice:

He's unsure whether to take the job or look for something else. 

Using Good Punctuation in Your Sentences

Because compound-complex sentences are so... well, complex, they can end up being quite long. To avoid confusing, run-on sentences, ensure you're using the correct punctuation to break them up.

Make good use of commas to separate your clauses. But be wary of using too many, and use semicolons where possible instead. For example, look at the following compound-complex sentence, which begins with two independent clauses, the first of which already contains three commas, so I use a semicolon to separate the two clauses.

My dogs Rex, Lex and Fox, which are all labradors, love swimming; I take them to the river everyday before I have breakfast.

If we hadn't used a semicolon and had instead used a comma and coordinating conjunction, the sentence would look like this:

My dogs Rex, Lex and Fox, which are all labradors, love swimming, so I take them to the river everyday before I have breakfast.

It is still correct, but more challenging to read and not as classy because of all the commas. Another option is to replace some commas with em dashes:

My dogs Rex, Lex and Fox—which are all labradors—love swimming, so I take them to the river everyday before I have breakfast.

Often there are many options; the idea is to get creative! Familiarize yourself with good punctuation practice, as this is something you'll always use.

Compound-Complex Sentence Examples

Now that we've covered the ins and outs of a compound-complex sentence let's look at more examples of this type of sentence.

After they got home, Jane went to her room, and Sally watched TV.

Every morning before brushing his teeth, John ate a bagel for breakfast, and he drank a cup of coffee, even though he hated the taste.

Donna just had to say hello whenever she saw a dog on the street, but she always asked the owner first.

We can eat in the dining room, or if you would prefer, we can eat in the garden.

Whenever her housemates cooked they never did the washing up; that's why she moved out.

Concluding Thoughts on Compound-Complex Sentences

That concludes this article on compound-complex sentences. I hope you found it helpful and that you feel equipped to use them in your writing.

Here's what we've learned:

  • A sentence is a group of words joined together to form a thought.
  • There are four types of sentence structure, and compound-complex sentences are one of them.
  • Compound-complex sentences comprise two or more independent clauses and at least one dependent clause.
  • Watch your punctuation to avoid run-on sentences and comma splices.

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Written By:
Carly Forsaith
Carly Forsaith is one of the lead freelance writers for Carly is a copywriter who has been writing about the English language for over 3 years. Before that, she was a teacher in Thailand, helping people learn English as a second language. She is a total grammar nerd and spends her time spotting language errors on signs and on the internet.

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