Sentences are the foundation of our language. Without them, we'd have nothing more than words with no clear way to connect. However, not all sentences are alike. We use different types of sentences to convey and connect different ideas, giving our words even more meanings than they would have otherwise.
The types of sentences then fall into what's known as sentence structures. These refer to the different ways that the different parts of a sentence come together. When you understand the different types of sentence structures, you can then see how larger ideas come together and convey your thoughts much more clearly.
Of course, that brings into question of just what is a sentence? Grammatically, a sentence needs at least two things: a subject and a verb.
Subjects can either be direct (as the word "subject" is in this sentence) or implied (as "you" often is when giving a command to someone else). Without both these elements, you only have a fragment, which often fails to convey your ideas fully—and if you don't have a complete thought, you're short a sentence, too.
But since there are more parts of speech than just subjects and verbs, there's a lot that can go into a sentence. Adding these different components can ultimately change the information in a sentence by changing the structure.
Most of us are familiar with simple sentences. We see and say them all the time. A simple sentence contains only one independent clause—a part of speech that expresses a complete thought and stands on its own. Independent clauses don't need anything else to be grammatically correct.
All but one of the sentences in the paragraph above are simple sentences. A few more examples include:
- She drank her coffee.
- I called my mom.
- The weather was nice.
- He and his friends cleaned out his car.
While the last sentence has a compound subject, it's still a simple sentence since there's only one complete thought. It's also possible to have compound verbs and objects in a simple sentence. The key is to remember that there's only one complete thought happening in these sentences, and that's what makes them "simple."
Compound sentences contain at least two independent clauses, and they're useful for communicating related thoughts and subjects. You make a compound sentence by using coordinating conjunctions, or you can use a semi-colon. Each part of a compound sentence must be complete on its own, and you should be able to take the conjunction out and have two complete sentences.
Coordinating conjunctions are what make compound sentences possible, and they consist of several different words. The major coordinating conjunctions are for, and, nor, but, or, yet, and so; you can use the acronym FANBOYS to remember them. The coordinating conjunction you use will indicate how the independent clauses relate to each other.
Some more examples of compound sentences include:
- The cat walked up to the girl, and she started to pat it.
- Tommy wanted chips for a snack, but his mom said no.
- Sarah could go to the concert, or she could go to the movies.
- Joe packed the food, Tania packed the drinks, and their parents checked their work before leaving.
Compound sentences can also make use of semicolons (;) instead of coordinating conjunctions. For example, you could write the second sentence above as "Tommy wanted chips for a snack; his mom said no." Generally, if you use a semi-colon, you don't need to use a coordinating conjunction, but some complex sentences can necessitate one.
However, you can only skip out on the coordinating conjunction if you use a semi-colon. If you use a comma without including a coordinating conjunction, you've written a type of run-on sentence known as a comma splice.
While simple and compound sentences work with independent clauses, complex sentences use dependent clauses. These clauses have subjects and verbs, but they don't express a complete thought. The opening phrase in the first sentence of this paragraph is a dependent clause—you wouldn't say "While simple and compound sentences work with independent clauses" as a complete sentence.
A dependent clause often elaborates on the rest of an idea in a sentence. Some examples of complex sentences are:
- When she asked about what was for breakfast, no one knew the answer.
- He became the unofficial DJ because he had the broadest music collection.
- If the others knew what was happening, they weren't letting him in on the secret.
If a dependent clause appears at the beginning of a sentence, it has a comma to separate it from the independent clause. However, commas generally don't need to divide the two if the independent clause comes first.
Because they both involve two clauses, it can be challenging to tell complex and compound sentences apart. The critical thing to remember is that the clauses in a compound sentence can both stand on their own as complete thoughts and they generally use coordinating conjunctions. Complex sentences include dependent clauses, which sometimes have words like if, when, because, and although to connect ideas.
Dependent clauses don't need to attach to an otherwise simple sentence structure. Instead, they can also connect to compound sentences, making a compound-complex sentence. To count as this type of sentence, there need to be at least two independent clauses and one dependent clause. Sentences that have more than those basic requirements are still compound-complex sentences.
Dependent clauses can relate to just one independent clause or both; it all depends on what is happening in the sentence. Compound-complex sentences often best communicate complex ideas that have several parts, so it's critical to carefully set up the wording so that the reader can understand what's happening.
Numerous sentences can be examples of compound-complex sentences:
- He joined the tournament because he received an invitation, and she bought him a good luck gift.
- While getting ready for company to come over, Jeremy took care of the cleaning and Kat cooked pizza for dinner.
- Although the weather was terrible, they left for their picnic; by the time they had arrived, the sun had come back out.
- During the summer, I swim, Tammy sunbathes, and Cory surfs.
Just like with simple sentences, it's important to remember that length isn't what determines the type of a sentence—it's all about what kinds of clauses make up the idea. With all sorts of sentences, it can help to diagram it to understand how the parts connect to get a better grasp on what they talk about and how you can use them.
The Importance Of Sentence Variation
If everyone only used simple sentences, communication would quickly become very dull and monotonous. However, if we just used complex, compound, and compound-complex sentences, we would always be looking for more information to fill out our words—or be too busy piecing together the different clauses to get any real meaning out of what each other is saying.
The key is then to introduce variation whenever you're communicating. When speaking, many of us change up the sentence structure we use without even thinking of it. After all, each sentence structure has its best uses, and we've heard enough variation throughout our lives that we instinctively understand when to mix it up.
Writing can be a little more complicated, especially since you can start to see when you're overusing a type of sentence or not enough of another. Sticking to one kind of sentence structure can quickly mean that you lose your audience to either boredom or confusion. Variations in sentence structure keep you from falling into that trap and give you a way to communicate your ideas better.
How Do You Know When To Use Different Sentence Structures?
If you're making a conscious effort to select sentence structures, you're on the path to more effective communication. However, not one sentence type if superior to the others; they all have their purpose for conveying ideas and contributing to your flow. When writing, consider these tips for selecting your sentence structure:
- Make sure that every sentence expresses complete and clear information.
- Sentences should stress the main point or idea, which is usually in the main clause to make it easily identifiable.
- Think of how the sentence structure can impact the rhythm and pacing of your work.
- Work to include the necessary information as clear and concise as possible; don't write a complex-compound sentence when a simple one will do.
- Consider the reading level and needs of your audience.
Understanding the purpose of your writing can help keep you focused. When you have a clear idea of what you want your work to accomplish and who will be reading it, you can then select the sentence structure that will best convey your idea. If you reread your work and discover that it doesn't have the best flow, then mixing up your sentence structure choices can help.
For the most part, writers use a combination of these four sentence types throughout their writing. By understanding how the types of structures work and learning to recognize them, you can make more informed decisions in your work.