5.1.2: Working with Language- Complex Sentences

The third in our series on sentence structure is complex sentences. Using a variety of sentence types (simple, compound, and complex) will make your writing more sophisticated.

What Is a Complex Sentence?

Like compound sentences, complex sentences have two clauses. Look at this sentence. The subjects are bold, the predicates (verb phrases) are underlined, and the conjunction is in italics.

• Camilla quit her job when she received a gift of $6,000.

There are two clauses here, but they are not equal:

• Camilla quit her job – this can stand alone.
• When she received a gift of $6,000 – this does not have a complete meaning without the first part.

The first clause is an independent clause. The second is a dependent clause: it needs the first clause to give it meaning. It cannot stand alone.

Dependent clauses begin with subordinating conjunctions (aka subordinators). The chart below shows a list of common subordinating conjunctions sorted by their functions in a sentence.

Common Subordinating Conjunctions

Time	Reason	Contrast	Unexpected Result
when before after while whenever once as soon as	because since as	whereas while although though	although though even though

Condition	Purpose	Relative Pronoun	Imaginary Comparisons
if whether unless as long as until	so that	that which who whom whose	as if as though

 

Complex Sentences--Examples

• As soon as I got home from school, I ate a sandwich.
• I ate a sandwich as soon as I got home from school.
• You look as though you have seen a ghost.
• The boy ran home as if a killer was chasing him.
• My students have trouble writing sentences, whereas I can write sentences easily.*
• Texas is a large state, while Connecticut is quite small.*
• I took a bus downtown on Saturday so that I could save money on gas and parking.
• Unless you study hard for the final exam, you will not get a passing grade.
• My friend failed the examination even though she studied hard.
• The women who hit my car showed me her insurance papers.

How to punctuate complex sentences:

                  Dependent Clause      ,       Independent Clause

Although I am usually afraid of dogs, I love my sister's dog, Rex.

In this case, the subordinator that begins the dependent clause (although) de-emphasizes the fact that the writer is usually afraid of dogs because that is the clause the subordinator begins. A comma is placed between the two clauses because the dependent clause is at the beginning of the sentence.

  Independent Clause         Dependent Clause

I love my sister's dog, Rex although I am usually afraid of dogs.

Here, the dependent clause (beginning with "although") is at the end of the sentence. No comma separates the two clauses.

Another example

Because I was hungry, I ate a sandwich.

I ate a sandwich because I was hungry.

To repeat: Dependent clauses must be used with independent clauses. If the dependent clause is first, a comma separates the two clauses. If the dependent clause comes after the independent clause, no comma is needed. 

However, there is an exception!

When you use while and whereas to express contrast, a comma is used before the dependent clause. However, this is not true when while is used in a time clause.

• John loves to swim in the ocean, while Sherry only likes swimming in the neighborhood pool.
• The math class was challenging for Joe, whereas the English class was relatively easy.
• We watched the football game while the children were playing outside.

Exercise 5.4

Combine the simple sentences below to make one complex sentence using a subordinator. There may be more than one correct answer.

1. His mother was a single parent. She always bought presents at Christmas.

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2. He lost a lot of weight. He was able to play sports.

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3. Houston is a big, urban city. Seguin is a small, rural town.

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4. I would love to write a novel. I don’t have enough patience to sit and write.

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5. Sam was driving home from work. He saw a bear on the road.

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6. I often leave campus late at night. I always feel nervous.

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7. Take a map on your hike in the mountains. You won't get lost.

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8.  You drive east from Houston on I-10. You will eventually come to Louisiana.

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Exercise 5.5

Correct punctuation errors In the following paragraph by adding or removing punctuation marks. Do not use semicolons. There are ten mistakes in punctuation in the paragraph. (Some mistakes require more than one change.) Remember to place commas after any element that comes before the subject of an independent clause.

After they finished the first dog/people training course at the SPCA Diane decided to sign Buster up for the next level class, which required more socialization. Diane knew this

would be a useful experience for Buster, because he growled at other dogs when she took him on walks. Because of this she started walking across the street whenever she

saw another dog approach. As a result Buster received less socialization. She was worried about whether the strategies from class would work  On the other hand if she didn't

bring him to the class his behavior would not improve because he could only learn with other dogs around him. The first session did not go well. Therefore the instructor asked

Diane and Buster to work one-on-one with a trainer. Although, Diane knew this would be more expensive, she figured it was a bit like having a child: Sometimes you have to

pay for things, although you'd rather not. In the end, it would be the best for both of them.

Exercise 5.6: 

Use the following subordinators to make original complex sentences. (Write your own sentences!)

1. although

2. because

3. while

4. after

5. if

6. unless

7. even though

8. until