We can combine two or more simple sentences into a complex sentence by changing all clauses except one into dependent clauses. One clause should be retained as an independent clause. That independent clause will be the principal verb in the sentence thus formed.

We have already learned that a complex sentence contains one main clause and one or more subordinate or dependent clauses. The dependent clause can be an adverb clause, an adjective clause or a noun clause.

An adjective clause usually describes a person or thing. An adverb clause indicates ideas such as time, place, cause, reason, manner or frequency. A noun clause can serve as the subject or object of a verb.

To start with

Try to identify the purpose served by each clause. See if one of the two clauses can act like the subject or object of the verb in the other clause. If it is possible, then you can change that clause into a noun clause. A noun clause is usually introduced by a conjunction like that. Other conjunctions like if and whether are also used to introduce noun clauses.

Study the examples given below.

• You are bent on mischief. It is known to everybody.

What is known to everybody? That you are bent on mischief

As you can see the clause ‘that you are bent of mischief’ can be the subject of the verb ‘is known’.

• That you are bent on mischief is known to everybody.

Another example is given below.

• There should be no spelling mistakes in your essay. Always remember that.

Always remember what? – That there should be no spelling mistakes in your essay

Here the noun clause ‘that there should be no spelling mistakes in your essay’ acts like the object of the verb remember.

• Always remember that there should be no spelling mistakes in your essay.