What is a complex sentence?

• A complex sentence communicates more than one idea.
• One part (the main clause) is like a simple sentence: it can stand on its own.
• The other part (the minor clause) gives more detail about the simple sentence, but it cannot stand alone.

For instance, look at this sentence:

You can't persuade me to go to town, no matter how hard you try.

• The first part could be a simple sentence - it stands on its own.
• The second part, 'no matter how hard you try', is not a simple sentence and it doesn't stand on its own. It needs something else to make sense.

Here is another example:

When I arrived the angry dog barked.

• The main clause is 'the angry dog barked' because it has a subject and a verb and makes sense by itself.
• The minor clause is 'When I arrived'. Although it is a clause with a subject and a verb, it doesn't make sense on its own. It needs a main clause.

You can add more minor clauses to make an even more complex sentence: 'When I arrived the angry dog barked because it was hungry.'

Why use a complex sentence?

Complex sentences add extra detail and information, for example so that a reader is able to create a vivid picture in their mind. When creating your own piece of writing, it is useful to think about the effects you're creating for your reader by the extra length of the sentence as well as by the extra detail given.

Hard Times by Charles Dickens

'It was a town of machinery and tall chimneys, out of which interminable serpents of smoke trailed themselves for ever and ever, and never got uncoiled. It had a black canal in it, and a river that ran purple with ill-smelling dye, arid vast piles of building full of windows where there was a rattling and a trembling all day long, and where the piston of the steam engine worked monotonously up and down, like the head of an elephant in a state of melancholy madness.'

• Here, Dickens describes an imaginary industrial town called 'Coketown' using two long, complex sentences.
• These allow him to give a great deal of descriptive detail that create a very vivid image of this industrial landscape.
• Dickens wants his reader to have a strong sense of place and the use of the complex sentences allows him to do this.