This page about sentence structure will focus on the differences between simple sentences, compound sentences, complex sentences and compound-complex sentences.
You must know how to correctly write these sentence types for IELTS as the examiner will be looking for them when they grade you for your 'grammatical range'.
Clauses are the buliding blocks of sentences. So, before you go any further, make sure you understand what clauses are by looking at the previous lesson. At the end there is a quiz to test yourself.
A simple sentence is one clause with a subject (S) and verb (V).
However, it can have more than one subject and verb:
2 subjects (SSV):
2 Verbs (SVV):
2 subject and 2 verbs (SSVV):
A compound sentence consists of 2 or 3 clauses. It is when simple sentences are joined together. In this sentence structure, the clauses are joined with the following coordinating conjunctions:
F = for
A = and
N = nor
B = but
O = or
Y = yet
S = so
The word 'fanboys' is an easy way to remember the different conjuntions that make up compound sentences. Obviously the most common are 'and', 'but', 'or' and 'so'.
Here are some examples of compound sentence structure:
Computers are important, but they can be dangerous too.
Computers are important, but they can be dangerous too, so we must be careful.
Avoid writing too many clauses as the sentence may get difficult to follow, and you cannot use each one more than once in a sentence to join clauses.
This is wrong:
Computers are used widely in most countries now and they are a sign of progress, and everyone should own one.
Two possible corrected versions:
Computers are used widely in most countries now and they are a sign of progress. Everyone should own one.
Computers are used widely in most countries now and they are a sign of progress so everyone should own one.
Using semicolons
There is an instance when you can have a compound sentence structure without a coordinating conjuntion, and this is when you join two clauses with a semicolon. It is used when two ideas are related.
For example:
Complex sentences are more complicated (which is maybe why they are called 'complex'!).
This type of sentence structure is important for IELTS because to get awarded a band 6 or higher for your 'grammatical range and accuracy', you need to demonstrate that you are able to use them.
The more varied and the more accurate your complex sentences are, the higher the band score for this.
There are different types of complex sentences and these will be looked at in more detail later, so here you are just provided with the basics.
Complex sentences are two (or more) clauses joined together, but they are not joined by 'fanboys' (coordinating conjuntions). They are joined by subordinating conjuntions.
These are subordinating conjunctions:
after |
even if |
unless |
For example:
These are all adverbial clauses. In these types of complex sentence, the second clause can be used to start the sentence. In this case, a comma is needed in the middle.
Noun clauses and relative clauses are also a type of complex sentence structure.
Compound-complex sentences are the same as complex sentences but they also have a simple (or compound) sentence before or after the 'complex' part.
For example:
The part that is underlined is the complex sentence. As you can see, it also has a simple sentences connected to it. It can also have a full compound sentence attached to it:
These are compound-complex sentences.
Multiple Choice
Identify what type of sentence each is.
There is just one independent clause so it is simple.
'Because' should tell you it is a complex sentence.
'Even though' should tell you it is a complex sentence.
The coordinating conjunctions (but, so) tell you it is compound. There is no subordinating conjunction so it cannot be complex or compound-complex.
The sentence has a subordinating conjunction (because) and a coordinating conjunction (so).
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