Complex Sentences
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Basics on the topic Complex Sentences
Complex Sentence – Definition
What is a complex sentence? A complex sentence contains a main clause and a subordinate clause. See example:
| Main clause | Subordinate clause |
|---|---|
| Jimmy finished reading the book | while he was waiting for a bus. |
What is the difference between a main and a subordinate clause?
- A main clause is a clause that can be a sentence on its own. It expresses a complete thought.
- A subordinate clause cannot stand alone as a sentence. It doesn’t convey a complete thought, and it is usually used to add an additional piece of information to the main clause.
Complex Sentences – Examples
To better understand the complex sentence structure, let’s have a look at this example of a complex sentence:
There are two clauses in this complex sentence example - a main clause (”She wore a hat and gloves”) and a subordinate clause (”because it was cold”). Do you see the difference? The subordinate clause because it was cold cannot be a sentence on its own. Though, it provides additional information by telling us why she wore a hat and gloves. Note: a main clause in a complex sentence can also be called an independent clause and a subordinate clause can also be called a dependent clause. Let’s practise with another example! Which of the following is a complex sentence?
- Jack had a wonderful morning today.
- Sarah called her best friend after she finished her homework.
- They were tired after a long walk in the park next to their house.
So which statement is an example of a complex sentence? It is sentence number 2! Why is this a complex sentence? Because it has a main clause (Sarah called her best friend) and a subordinate clause (after she finished her homework).
| Main clause | Subordinate clause |
|---|---|
| Sarah called her best friend | after she finished her homework. |
| can be a sentence on its own | cannot stand alone as a sentence |
| expresses a complete thought | doesn’t express a complete thought, but adds a piece of information to the main clause |
Complex Sentences with Subordinating Conjunctions
Now you can recognise a complex sentence. But how to make a complex sentence? There are different complex sentence types, but usually we make a complex sentence using a subordinating conjunction. Let’s find out what subordinating conjunctions are.
Subordinating conjunctions are words that link subordinate clauses to main clauses. They help us to build complex sentences.
Subordinate clauses usually start with a subordinating conjunction. There are plenty of subordinating conjunctions, but here are the most common ones:
- after
- before
- because
- although
- when
- since
- whenever
- unless
- while
- so
- until
- as
Let’s come back to our first example. Can you find a subordinating conjunction?
Because is a subordinating conjunction. It comes at the beginning of the subordinate clause and unites two clauses together in a complex sentence.Here are more examples of complex sentences with subordinating conjunctions:
| Main clause | Subordinating conjunction | Subordinate clause |
|---|---|---|
| I won't win the competition | unless | I practise every day. |
| Mary’s dog barks | whenever | I walk by her house. |
| You should call your parents | after | you finish your lunch. |
Complex Sentence Structures
Complex sentences can be written either with a subordinate or a main clause first.
Have a look at these two sentences:
If a subordinate clause comes first, we use a comma before a main clause. In the sentence above, a comma stands before Mum brings me my lunch, which is a main clause.
Complex Sentence – Summary
Let’s review what we learnt about complex sentences and subordinating conjunctions in this text.
A complex sentence is a sentence that contains a main clause and a subordinate clause. A main clause expresses a complete thought and can be a meaningful sentence on its own. A subordinate clause cannot be a full sentence, as it doesn’t express a complete thought. It usually provides extra information about the events described in a main clause. A subordinate clause usually starts with a subordinating conjunction. Subordinating conjunctions are special “complex sentence words” that connect a subordinate clause to a main clause. Complex sentences can be written with both subordinate and main clauses first. When a subordinate clause is first, we use a comma after it.
Now you know more about complex sentences. Want more practice? Watch our video and use our complex sentence worksheets! Did you enjoy our article about complex sentences? Complex sentences are one of the three types of sentences in English. You can learn more about other types and the differences between them on this platform. Check out the video on compound sentences to find out more!
Frequently Asked Questions about Complex Sentences
Transcript Complex Sentences
Koko and Pip are on let's make a sentence! To win a lifetime of art supplies, they need to create complex sentences. A complex sentence is a type of multi-clause sentence and contains a main, or independent clause, and a subordinate or dependent clause. A main clause is a complete thought, so it can be a sentence on its own. It contains a subject and a verb. A subordinate clause also contains a verb but it cannot stand alone as a sentence because it doesn't express a complete thought; it usually provides more information. Here, we have the sentence, 'she wore a hat and gloves because it was cold.' In this example, 'she wore a hat and gloves' is a main clause. And, 'because it was cold' is a subordinate clause. The subordinate clause begins with a subordinating conjunction, which links subordinate clauses to main clauses! Subordinate clauses usually begin with a subordinating conjunction, such as after, before, because, although, when, since, whenever, unless, while, so and many more! Complex sentences can be written with the main clause first, like this one. However, you can write complex sentences with the subordinate clause first! This sentence can be rewritten as, 'Because it was cold, she wore a hat and gloves.' When the subordinate clause is first, we use a comma before the main clause. Koko and Pip have been given two clauses, and need to identify them correctly to win the art supplies! Let's join in! The clauses are; 'before she goes shopping', and 'Mum brings me my lunch'. Which is the main clause and which is the subordinate clause? Mum brings me my lunch is a complete thought, so it is the main clause. Before she goes shopping is not a complete thought because it starts with a subordinating conjunction, so it is the subordinate clause. How could Koko and Pip rewrite this sentence with the subordinate clause first? They can rewrite it as; before she goes shopping, Mum brings me my lunch. Whilst Koko and Pip see if they have won the lifetime of art supplies, let's review! Remember, complex sentences contain a main, or independent, clause and a subordinate, or dependent, clause. Main clauses can stand alone as a sentence. Subordinate clauses cannot stand alone as a sentence. Subordinate clauses usually begin with a subordinating conjunction. You can write complex sentences with the main clause first, or with the subordinate clause first. "I thought we would get the lifetime of art supplies delivered monthly, Pip, not all at once!"
Complex Sentences exercise
-
What does a complex sentence contain?
HintsA complex sentence contains two parts.
There are two correct answers.
Another name for a main clause is an independent clause.
Another name for a subordinate clause is a dependent clause.
SolutionA complex sentence contains a main clause and a subordinate clause.
-
What are the characteristics of main and subordinate clauses?
HintsIt was raining outside so we had to stay at home.
The part of this sentence in bold is the subordinate clause.
You have to finish your homework before watching TV.
The part of this sentence in bold is the main clause.
SolutionA complex sentence contains a main clause and a subordinate clause.
-
Can you identify the main and subordinate clauses in these sentences?
HintsA main clause is a sentence on its own.
Subordinate clauses usually begin with a subordinating conjunction, such as after, before, because, although, when, since, whenever, unless, while, so and many more!
SolutionComplex sentences can be written with the main clause or subordinate clause first. When the subordinate clause is first, we use a comma before the main clause.
-
Identify the missing subordinating conjunctions.
HintsSo means and for this reason.
Although means in spite of.
Check whereabouts in the sentence the subordinating conjunction goes. Does it need a capital letter or not?
SolutionHere are the correct answers:
- They were running to catch the bus because they were late.
- When Raj was five, he started school.
- They got dressed before breakfast.
- Although it was raining, Tom took the dog for a walk.
- Beth lost her pencils so she had to buy new ones.
-
Can you match the clauses of these complex sentences?
HintsSubordinate clauses can introduce reasons for or consequences of actions.
Why might someone be late for school?
What happened at the same time they were reading?
SolutionHere are the correct answers:
- He was late for school because he missed the bus.
- Although he felt full, he ate another slice of pizza.
- There was no one in the hallway so she knocked on the door.
- While they were reading, they received an email.
-
Can you identify the elements in the sentences?
HintsA subordinating conjunction links subordinate clauses to main clauses.
Subordinate clauses usually begin with a subordinating conjunction, such as after, before, although, when, since, unless, while and many more.
SolutionSubordinate clauses cannot stand alone as a sentence. Subordinate clauses usually begin with a subordinating conjunction.
Here we can see the main clauses in violet and the subordinate clauses in blue. The subordinating conjunctions are in green.
