Compound Complex Sentences

Ah, the compound-complex sentence. This term sounds ... complex. But don't worry! When you've got a few key terms and characteristics down, you'll find that compound-complex sentences aren't as complex as they seem.

Definition of a Compound-Complex Sentence

A compound-complex sentence is a combination of two other sentence types: the compound sentence and the complex sentence.

Put these definitions together, and you have the definition of a compound-complex sentence.

A few more definitions are necessary to completely understand this concept. Here is a general refresher.

• The subject of a sentence is what the sentence is about. It primarily consists of a noun or pronoun.
• The predicate of a sentence is what describes the subject. It primarily consists of a verb.
• A clause is a meaningful group of words made up of a subject and a predicate.
• There are two types of clauses: independent and dependent.
  • An independent clause (also called a main clause) is a clause that can exist alone as a full sentence.
  • A dependent clause (also called a subordinate clause) is a clause that can't exist alone as a full sentence.
• A coordinating conjunction is a word that joins two words, phrases, or clauses (like and, but, and or).
• A subordinating conjunction is a word that introduces a dependent clause (like where, that, and which).

In this StudySet, pink text marks independent clauses, blue text marks dependent clauses, and purple text marks coordinating conjunctions.

Characteristics of a Compound-Complex Sentence

As the definition states, a compound-complex sentence has to have at least two independent clauses, like a compound sentence. Here is an example of this condition.

A compound sentence is basically two simple sentences squished together.

This sentence consists of two independent clauses: My mom dropped us off at school and Max brought us back home. Each clause can exist as its own sentence. They are joined with the coordinating conjunction and.

The independent clauses in a compound sentence are joined with a semicolon or with a coordinating conjunction (like and, but, and or).

When you remove the semicolon or coordinating conjunction, each clause can stand alone as a simple sentence. Both clauses in each sentence are independent clauses.

A compound-complex sentence also has to have at least one dependent clause, like a complex sentence. Here is an example of a complex sentence:

The first clause, please feed the cat, is an independent clause. It can exist as a complete sentence. The second clause, before you leave today, doesn't make a full sentence without the first clause. This is a dependent clause.

A dependent clause can start with words like before, that, since, if, when, where, and after. In this context, these words are called subordinating conjunctions.

The first clause in this example is the dependent clause: if we're going to be late anyway. The second is the independent clause: we might as well stop for lunch.

Fig. 1 - A dependent clause has to cling onto an independent clause in a compound sentence.

A compound-complex sentence has to behave as both a compound sentence and a complex sentence.

• A compound-complex sentence must contain two or more independent clauses.
• A compound-complex sentence must contain one or more dependent clauses.

Any sentence that meets these two criteria is a compound-complex sentence.

Function of a Compound-Complex Sentence

Sometimes a string of short, simple sentences can't effectively express a complicated thought. It can make your writing seem stunted and awkward to a reader. Compound-complex sentences combine these simple sentences into longer strings of thought.

These four sentences get their message across, but they do it inefficiently. A compound-complex sentence could communicate this message more effectively.

This example combines all the previous sentence's examples into a compound-complex sentence. This sentence flows better and gets its point across more effectively.

Compound-complex sentences aren't always the best option—sometimes simpler is better!—but in the right context, they create effective persuasion and elegant writing.

Types of Compound-Complex Sentences?

All sentences, including compound-complex sentences, are divided into four types based on their purpose of communication: declarative, interrogative, exclamatory, and imperative.

Declarative Compound-Complex Sentence

The compound-complex sentences you've seen so far have been declarative. Declarative sentences declare that something is true or false.

In this example, the two independent clauses are I can take you home and Patrick will be coming too. The independent clauses are joined by the coordinating conjunction but. The dependent clause is after the game is over. The sentence makes a clear statement and ends with a period.

Interrogative Compound-Complex Sentence

Another purpose of communication is interrogation. The word may sound threatening, but it simply refers to asking questions.

In this example, the two independent clauses are are you working the closing shift and are you free to go out with us, joined by the coordinating conjunction or. The dependent clause is after we finish school today. The sentence asks a question and ends with a question mark.

Exclamatory Compound-Complex Sentence

An exclamatory sentence is a declarative sentence with intensity. It exclaims, rather than simply stating.

This example's two independent clauses are I would have had some after work and Ellie would have taken some for lunch, joined by the conjunction and. The dependent clause is if you hadn't eaten the whole pie. The sentence ends with an exclamation point, signaling an exclamatory compound-complex sentence.

Imperative Compound-Complex Sentence

An imperative sentence commands its subject to do something.

The independent clauses are please go get the mail and take your little sister with you, joined by the conjunction and. The dependent clause is when you get home. The sentence makes a command and ends with a period.

Examples of Compound-Complex Sentences

Certain sentence structure elements, like prepositional phrases, compound subjects, and compound predicates, can disguise themselves as independent and dependent clauses. This can make it difficult to recognize a compound-complex sentence. Here are some tricky examples.

Compound-Complex Sentences vs. Prepositional Phrase

Many subordinating conjunctions that signal dependent clauses also function as prepositions. Sometimes, these words disguise prepositional phrases as dependent clauses.

In this example, before work seems like a dependent clause. Notice, though, that it doesn't contain a verb. Because it doesn't have a predicate, before work is a prepositional phrase, not a dependent clause. Without a dependent clause, this is not a compound-complex sentence.

If this example were a compound-complex sentence, it would look like this:

Before I go to work has both a subject and a predicate, making it a clause.

Compound-Complex Sentence vs. Compound Subject

Coordinating conjunctions join two independent clauses, but they also join other sentence elements. In this example, a coordinating conjunction joins two subjects, not two independent clauses.

The coordinating conjunction and connects Mady and I, forming a compound subject. The subjects belong to just one independent clause. With only one independent clause, this is not a compound-complex sentence.

As a compound-complex sentence, this example would look like this:

The predicate is now repeated for each subject, separating a single clause into two independent clauses.

Compound-Complex Sentence vs. Compound Predicate

Like compound subjects, compound predicates are easily confused with independent clauses.

At a glance, she just jumped out of the bus and rode away on her bike seem like two independent clauses. But there is one issue. The subject she appears before jumped out of the bus, but not before rode away on her bike. Because the two verb phrases share one subject, they are part of the same clause. With just one independent clause, this sentence can't be compound-complex.

Fig. 2 - They ride their bike as skillfully as they write compound-complex sentences.

This example as a true compound-complex sentence would look like this:

The subject she now appears before jumped off the bus and before rode away on her bike, forming two distinct, independent clauses.

If you're unsure whether a sentence is compound-complex, follow these steps:

• Identify every clause by asking yourself, "does this group of words include both a subject and a predicate?"
• Determine whether each clause is dependent or independent.
• Count the dependent and independent clauses. If there are at least two independent clauses and at least one dependent clause, the sentence is compound-complex.