Back when I was in the ESL career, I taught technical and creative writing to some of the advance students we had. One of the basic topics I covered is the sentence structure (or types of sentences). I usually give at least a week to discuss all the elements of a sentence with my students—that includes the purpose, order, and type of a sentence. Now, why would I take that much time to discuss it?
To illustrate, just as a good craftsman uses different gears and tools, a good writer uses different types of sentences in different situations:
- a long complex sentence will show what information depends on what other information,
- a compound sentence will emphasise balance and parallelism,
- a short simple sentence will grab a reader’s attention,
- a loose sentence will tell the reader in advance how to interpret your information,
- a periodic sentence will leave the reader in suspense until the very end,
- a declarative sentence will avoid any special emotional impact;
- an exclamatory sentence, used sparingly, will jolt the reader;
- an interrogative sentence will force the reader to think about what you are writing, and
- an imperative sentence will make it clear that you want the reader to act right away.
Types of Sentence Structures
The most basic type of sentence is the simple sentence, which contains only one clause. A simple sentence can be as short as one word:
Eat! [where the subject you is omitted since it is already understood]
Usually, however, the sentence has a subject as well as a predicate and both the subject and the predicate may have modifiers. All of the following are simple sentences, because each contains only one clause:
The ice melts quickly.
The ice on the river melts quickly under the warm March sun.
Lying exposed without its blanket of snow, the ice on the river melts quickly under the warm March sun.
As you can see, a simple sentence can be quite long—it is a mistake to think that you can tell a simple sentence from a compound sentence or a complex sentence simply by its length.
A simple sentence can also contain a compound subject and/or compound verb/predicate.
Kaiih went to the concert and had pizza after that. [compound verbs]
Kaiih and Josh went to the concert. [compound subject]
Kaiih and Josh went to the concert and had pizza after that. [compound subject and verb]
A compound sentence is made up of two or more independent clauses (or simple sentences) joined by coordinating conjunctions like and, but, and or (FANBOYS conjunction).
London is an interesting country. [simple sentence]
It has a lot of cheeky people. [simple sentence]
London is an interesting country, and it has a lot of cheeky people. [compound sentence]
Compound sentences are very natural for English speakers—mall children learn to use them early on to connect their ideas and to avoid pausing (and allowing an adult to interrupt):
Today at school, Mr. Moore brought in his pet rabbit, and he showed it to the class, and I got to pet it, and Kate held it, and we coloured pictures of it, and it ate part of my carrot at lunch, and . . .
Of course, this is an extreme example, but if you overuse compound sentences in written work, your writing might seem immature.
A compound sentence is most effective when you use it to create a sense of balance or contrast between two (or more) equally important pieces of information:
The United States has made famous movies, but the United Kingdom is known to be the home of household music celebrities.
A complex sentence contains one independent clause and at least one dependent clause. Unlike a compound sentence, however, a complex sentence contains clauses which are not equal.
My friend invited me to visit London. I did not want to go. [two simple sentences]
My friend invited me to visit London, but I did not want to go. [compound sentences]
Although my friend invited me to visit London, I did not want to go. [complex sentence]
In the first example, there are two separate simple sentences: “My friend invited me to visit London” and “I had no money for the trip.” The second example joins them together into a single sentence with the coordinating conjunction but, but both parts could still stand as independent sentences—they are entirely equal, and the reader cannot tell which is most important. In the third example, however, the sentence has changed quite a bit: the first clause, “Although my friend invited me to visit London,” has become incomplete, or a dependent clause.
A complex sentence is very different from a simple sentence or a compound sentence because it makes clear which ideas are most important. When you write
My friend invited me to visit London. I did not want to go.
My friend invited me to visit London, but I did not wan to go.
The reader will have trouble knowing which piece of information is most important to you. When you write the subordinating conjunction although at the beginning of the first clause, however, you make it clear that the fact that your friend invited you is less important than—or subordinate—to the fact that you do not want to go.
A compound complex sentence contains multiple independent clauses and at least one dependent clause.
My friend invited me to visit London, but I did not want to go because I had no money for the trip.
The dependent clause that is appended to the independent clause in this example provides additional information why you did not want to go.
A loose sentence introduces the main point right away.
I prefer to be called Keith, but my friends have established calling me Kirby.
Loose sentences are the most natural for English speakers, who almost always talk in loose sentences: even the most sophisticated English writers tend to use loose sentences much more often than periodic sentences. While a periodic sentence can be useful for making an important point or for a special dramatic effect, it is also much more difficult to read, and often requires readers to go back and reread the sentence once they understand the main point.
Finally, it is important to remember that you have to structure a loose sentence as carefully as you would structure a periodic sentence: it is very easy to lose control of a loose sentence so that by the end the reader has forgotten what your main point was.
A periodic sentence does otherwise; it usually introduces an element or series of elements to support the main point before getting to it directly.
Even though I have tried introducing myself to newly met acquaintances as Keith and told my friends that I prefer to be called Keith, they still call me Kirby.
The periodic sentence has become much rarer in formal English writing over the past hundred years, and it has never been common in informal spoken English (outside of bad political speeches). Still, it is a powerful rhetorical tool. An occasional periodic sentence is not only dramatic but persuasive: even if the readers do not agree with your conclusion, they will read your evidence first with open minds. If you use a loose sentence with hostile readers, the readers will probably close their minds before considering any of your evidence.
Finally, it is important to remember that periodic sentences are like exclamatory sentences: used once or twice in a piece of writing, they can be very effective; used any more than that, they can make you sound dull and pompous.