Building Sentences

Some English sentences are very basic:

Shakespeare was a writer.
Einstein said something.
The Inuit are a people.

You could write an entire essay using only simple sentences like these:

William Shakespeare was a writer. He wrote plays. It was the Elizabethan age. One play was Hamlet. It was a tragedy. Hamlet died. The court died too.

It is not likely, however, that your essay would receive a passing grade. This chapter helps you learn to recognise different types of sentences and to use them effectively in your own writing.

Written by David Megginson

Why Sentence Structure Matters

Although ordinary conversation, personal letters, and even some types of professional writing (such as newspaper stories) consist almost entirely of simple sentences, your university or college instructors will expect you to be able to use all types of sentences in your formal academic writing. Writers who use only simple sentences are like truck drivers who do not know how to shift out of first gear: they would be able to drive a load from Montréal to Calgary (eventually), but they would have a great deal of trouble getting there.

If you use phrases and clauses carefully, your sentences will become much more interesting and your ideas, much clearer. This complex sentence develops a major, central idea and provides structured background information:

Since it involves the death not only of the title character but of the entire royal court, Hamlet is the most extreme of the tragedies written by the Elizabethan playwright William Shakespeare.

Just as a good driver uses different gears, 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.


Written by David Megginson

The Structure of a Sentence

Remember that every clause is, in a sense, a miniature sentence. A simple sentences contains only a single clause, while a compound sentence, a complex sentence, or a compound-complex sentence contains at least two clauses.

The Simple Sentence

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:


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:

Ice melts.
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.

The most natural sentence structure is the simple sentence: it is the first kind which children learn to speak, and it remains by far the most common sentence in the spoken language of people of all ages. In written work, simple sentences can be very effective for grabbing a reader's attention or for summing up an argument, but you have to use them with care: too many simple sentences can make your writing seem childish.

When you do use simple sentences, you should add transitional phrases to connect them to the surrounding sentences.

The Compound Sentence

A compound sentence consists of two or more independent clauses (or simple sentences) joined by co-ordinating conjunctions like "and," "but," and "or":

Canada is a rich country.
Still, it has many poor people.
Canada is a rich country, but still it has many poor people.

Compound sentences are very natural for English speakers -- small 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 over-use 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:

Montréal has better clubs, but Toronto has better cinemas.

Special Cases of Compound Sentences

There are two special types of compound sentences which you might want to note. First, rather than joining two simple sentences together, a co-ordinating conjunction sometimes joins two complex sentences, or one simple sentence and one complex sentence. In this case, the sentence is called a compound-complex sentence:

The package arrived in the morning, but the courier left before I could check the contents.

The second special case involves punctuation. It is possible to join two originally separate sentences into a compound sentence using a semicolon instead of a co-ordinating conjunction:

Sir John A. Macdonald had a serious drinking problem; when sober, however, he could be a formidable foe in the House of Commons.

Usually, a conjunctive adverb like "however" or "consequently" will appear near the beginning of the second part, but it is not required:

The sun rises in the east; it sets in the west.

The Complex Sentence

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. Consider the following examples:

My friend invited me to a party. I do not want to go.
My friend invited me to a party, but I do not want to go.
Although my friend invited me to a party, I do not want to go.

In the first example, there are two separate simple sentences: "My friend invited me to a party" and "I do not want to go." The second example joins them together into a single sentence with the co-ordinating 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 a party," 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 a party. I do not want to go.

or even

My friend invited me to a party, but I do not want 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.


Written by David Megginson

The Order of a Sentence

Not all sentences make a single point -- compound sentences, especially, may present several equally-important pieces of information -- but most of the time, when you write a sentence, there is a single argument, statement, question, or command which you wish to get across.

When you are writing your sentences, do not bury your main point in the middle; instead, use one of the positions of emphasis at the beginning or end of the sentence.

The Loose Sentence

If you put your main point at the beginning of a long sentence, you are writing a loose sentence:

I am willing to pay slightly higher taxes for the privilege of living in Canada, considering the free health care, the cheap tuition fees, the low crime rate, the comprehensive social programs, and the wonderful winters.

The main point of this sentence is that the writer prefers to live in Canada, and the writer makes the point at the very beginning: everything which follows is simply extra information. When the readers read about the free health care, the cheap tuition fees, the low crime rate, the comprehensive social programs, and the wonderful winters, they will already know that these are reasons for living in Canada, and as a result, they will be more likely to understand the sentence on a first reading.

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.

The Periodic Sentence

If your main point is at the end of a long sentence, you are writing a periodic sentence:

Considering the free health care, the cheap tuition fees, the low crime rate, the comprehensive social programs, and the wonderful winters, I am willing to pay slightly higher taxes for the privilege of living in Canada.

The main point of this sentence is that the writer prefers to live in Canada. At the beginning of this sentence, the reader does not know what point the writer is going to make: what about the free health care, cheap tuition fees, low crime rate, comprehensive social programs, and wonderful winters? The reader has to read all of this information without knowing what the conclusion will be.

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.


Written by David Megginson

The Purpose of a Sentence

The other classifications in this chapter describe how you construct your sentences, but this last set describes why you have written the sentences in the first place. Most sentences which you write should simply state facts, conjectures, or arguments, but sometimes you will want to give commands or ask questions.

The Declarative Sentence

The declarative sentence is the most important type. You can, and often will write entire essays or reports using only declarative sentences, and you should always use them far more often than any other type. A declarative sentence simply states a fact or argument, without requiring either an answer or action from the reader. You punctuate your declarative sentences with a simple period:

Ottawa is the capital of Canada.
The distinction between deconstruction and post-modernism eludes me.
He asked which path leads back to the lodge.

Note that the last example contains an indirect question, "which path leads back to the lodge." An indirect question does not make a sentence into an interrogative sentence -- only a direct question can do that.

The Interrogative Sentence

An interrogative sentence asks a direct question and always ends in a question mark:

Who can read this and not be moved?
How many roads must a man walk down?
Does money grow on trees?

Note that an indirect question does not make a sentence interrogative:

When was Lester Pearson prime minister?
I wonder when Lester Pearson was prime minister.

A direct question requires an answer from the reader, while an indirect question does not.

The Rhetorical Question

Normally, an essay or report will not contain many regular direct questions, since you are writing it to present information or to make an argument. There is, however, a special type of direct question called a rhetorical question -- that is, a question which you do not actually expect the reader to answer:

Why did the War of 1812 take place? Some scholars argue that it was simply a land-grab by the Americans ...

If you do not overuse them, rhetorical questions can be a very effective way to introduce new topics or problems in the course of a paper; if you use them too often, however, you may sound patronising and/or too much like a professor giving a mediocre lecture.

The Exclamatory Sentence

An exclamatory sentence, or exclamation, is simply a more forceful version of a declarative sentence, marked at the end with an exclamation mark:

The butler did it!
How beautiful this river is!
Some towns in Upper Canada lost up to a third of their population during the cholera epidemics of the early nineteenth century!

Exclamatory sentences are common in speech and (sometimes) in fiction, but over the last 200 years they have almost entirely disappeared from academic writing. You will (or should) probably never use one in any sort of academic writing, except where you are quoting something else directly. Note that an exclamation mark can also appear at the end of an imperative sentence.

The Imperative Sentence

An imperative sentence gives a direct command to someone -- this type of sentence can end either with a period or with an exclamation mark, depending on how forceful the command is:

Read this book for tomorrow.

You should not usually use an exclamation mark with the word "please":

Wash the windows!
Please wash the windows.

Normally, you should not use imperative sentences in academic writing. When you do use an imperative sentence, it should usually contain only a mild command, and thus, end with a period:

Consider the Incas.


Written by David Megginson

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