Theory:

Different Kinds of Complex Sentences

The difference between simple sentences and complex sentences is that complex sentences allow the writer to give more detailed and more precise information about the basic idea expressed in the simple sentence.

For this we need to use a variety of grammatical structures, such as the present perfect, the conditional, the passive, relative clauses, concession and refutation, and inversion, using participle clauses

because that is what their function is.

Here we will look at how to use these grammatical structures, and the clauses and phrases we have discussed, to modify a simple sentence and create a more detailed complex sentence.

Smoking is today and has been for many years a serious problem for our society. (using the present perfect)

If smoking had been prohibited in the past, our hospitals would not be full of smokers today. (using the conditional)

Many people are affected by smoking. (using the passive)

Many people, who have never smoked, are affected by passive smoking. ( using relative clauses)

While smokers have the right to spend their money as they like, the should not waste it on cigarettes. (using concession)

Were smoking to be prohibited, there would be less people in hospital. (using inversion)

Having given up smoking, people feel they enjoy their lives more. (using participle clauses)