Theme: Compound and Complex sentence Content: introduction main part

Explanation of the combination of compound and complex sentence structures

As we mentioned in our guide on how to write better sentences, compound sentences combine two or more independent clauses. The key here is independent clauses, which are clauses that can stand alone as separate sentences. Essentially, a compound sentence brings together individual, related sentences as one.
(If you’re unfamiliar with these terms, please check out our guide to clauses in English, which better defines what makes up a clause.)
Compound sentences are easy to identify because they usually use a coordinating conjunction, which you may remember as FANBOYS: For, And, Nor, But, Or, Yet, and So. However, compound sentences can also use a semicolon to connect two clauses, in which case no conjunction is necessary.
Let’s look at some compound sentence examples to see how they work.
Compound sentence examples
Below are two simple sentences. Both are independent clauses because they each have their own subjects and verbs.
I have a pet iguana; his name is Fluffy.
To combine them into a compound sentence, we simply add a comma plus the coordinating conjunction and.
I have a pet iguana, and his name is Fluffy.
Alternatively, we can make a compound sentence by adding only a semicolon and the sentence is still correct.
I have a pet iguana; his name is Fluffy.
Although they’re talking about the same topic, the subjects of each sentence are both different: the first sentence’s subject is I and the second one’s subject is name. That’s part of what makes them independent, and compound sentences only work with independent clauses. For example, the sentence below is not a compound sentence.
I have a pet iguana whose name is Fluffy.
To be a compound sentence, it needs at least two subjects and two verbs. If both sentences use the same subject, it must be stated twice, as in the example below. Otherwise, it’s not a compound sentence.
“I alone cannot change the world, but I can cast a stone across the water to create many ripples.” —Mother Teresa
Be careful of sentences with two subjects or two verbs—these are not the same as compound sentences.[7] The following sentence is not a compound sentence because there is only one subject and because what comes after the conjunction “and” is not an independent clause:
I came here to chew bubble gum and study grammar.
However, you can turn this sentence into a compound sentence by adding another independent clause with a second subject:
I came here to chew bubble gum and study grammar, but I’m all out of gum.
Keep in mind that imperative sentences don’t always show their subjects because they’re assumed. That leads to compound sentences like this example:
Get me some water, or the fire will spread!
Let’s look at some more compound sentence examples from some of history’s greatest writers:
“Nature does not hurry, yet everything is accomplished.” —Lao Tzu
“Be yourself; everyone else is already taken.” —Oscar Wilde

As always, you use a lowercase letter to start the second independent clause. Since compound sentences are a single sentence, only the first letter of the first clause is capitalized. Mastering these punctuation rules is crucial for creating compound sentences. Without them, your sentence becomes a dreaded run-on sentence. In writing, run-on sentences are not only grammatically incorrect, but also they’re difficult for your reader to understand.[8] To avoid both run-on sentences and confusingly long compound sentences, try to limit the number of clauses in a sentence to two or three. In situations when you need more than three clauses, keep them as short as possible by removing unnecessary words. Remember, short sentences are easier to understand and give your writing a faster pace.

Compound vs. complex sentences
It’s easy to get compound sentences confused with complex sentences; both use two or more clauses in a single sentence. The most significant difference, however, is the type of clause they use.
Compound sentences use two or more independent clauses.
I am working now, but we will eat later.
Complex sentences combine independent clauses with subordinate clauses, also known as dependent clauses.
Because I am working now, we will eat later.
In this example, because I am working now is the subordinate clause and we will eat later is the independent clause. The clue is the word because, which is a subordinating conjunction. Words like because, if, whenever, and since—as well as certain prepositions like after and before—all act as subordinating conjunctions. Their job is to connect subordinate clauses to independent clauses. Just by adding a subordinating conjunction, you can turn an independent clause into a subordinating clause.[9] I am working now alone is an independent clause, but with because in front it becomes a subordinating clause. Be careful, though, because a sentence can be both complex and compound at the same time! A complex-compound sentence occurs when a single sentence has at least two independent clauses and at least one subordinate clause. After I got home from work, my friends invited me out, and I left my apartment again. In this example, after I got home from work is the subordinate clause (you can tell because the word after appears at the front). Both my friends invited me out and I left my apartment again are independent clauses, joined by the coordinating conjunction and. Put all three clauses together with the proper punctuation and you have a perfectly correct complex-compound sentence.
Combining compound and complex sentence structures in communication adds another layer of sophistication and versatility. While compound sentences join independent clauses, complex sentences incorporate both independent and dependent clauses.[10] This combination allows for the expression of complex relationships between ideas, introduces subordination, and offers greater depth in conveying information. Here's an explanation of the combination of compound and complex sentence structures:
Expressing Relationships and Subordination:
By combining compound and complex sentence structures, writers and speakers can express a variety of relationships and levels of importance between ideas. Compound sentences allow for the coordination of independent clauses, emphasizing equal significance, while complex sentences introduce subordination, highlighting dependent relationships.
Example:
Compound sentence: John loves playing basketball, and he excels at it.
Complex sentence: Although John loves playing basketball, he excels at it due to his dedication and consistent practice.
In this example, the compound sentence presents two independent clauses with equal emphasis, while the complex sentence adds a dependent clause to provide a reason for John's excellence in basketball.
Adding Nuance and Depth:
The combination of compound and complex sentence structures enhances the ability to convey nuanced information and delve deeper into a topic. Complex sentences introduce dependent clauses that provide additional details, examples, or explanations, enriching the overall message.
Example:
Compound sentence: The company expanded its operations, and its profits increased.
Complex sentence: Despite facing challenges, the company expanded its operations, and as a result, its profits increased significantly.
In this example, the complex sentence provides a deeper understanding of the cause-effect relationship between the challenges faced by the company, its expansion efforts, and the subsequent increase in profits.
Developing Coherent and Well-Structured Arguments:
The combination of compound and complex sentence structures contributes to the development of coherent and well-structured arguments. Compound sentences help connect related ideas, while complex sentences add supporting evidence, reasoning, or counterarguments, making the argument more comprehensive and persuasive.
Example:
Compound sentence: Recycling reduces waste, and it is good for the environment. Complex sentence: Recycling reduces waste, which minimizes pollution and conserves natural resources, ultimately benefiting the environment and future generations.
In this example, the complex sentence expands upon the benefits of recycling by introducing dependent clauses that provide specific reasons and emphasize the long-term environmental impact.
Varied Sentence Patterns for Engagement:
The combination of compound and complex sentence structures adds variety to communication, preventing monotony and enhancing engagement. By using different sentence patterns, writers and speakers capture the audience's attention and maintain their interest throughout the communication.
Example:
Compound sentence: She studied diligently, and she earned top grades in her exams.
Complex sentence: Despite her initial struggles, she studied diligently, and her efforts paid off with top grades in her exams. In this example, the compound sentence establishes a simple cause-effect relationship, while the complex sentence adds a dependent clause that highlights initial challenges, creating a more engaging narrative. In summary, combining compound and complex sentence structures allows for the expression of complex relationships, the addition of nuance and depth, the development of coherent arguments, and increased engagement. This combination enhances the overall effectiveness of communication, enabling writers and speakers to convey their ideas with clarity, precision, and impact.