Complex Sentences

A complex sentence consists of one main/independent clause and one or more subordinate clauses. The subordinate clause is usually introduced by a subordinating conjunction or relative pronoun.

There are three types of subordinate clauses.

Adjective clause – usually introduced by the relative pronouns who, which, that, whose, whom, where, what

Adverb clause – usually introduced by the subordinating conjunctions when, while, whereas, though, although, even though, even if, because, as, since, if, whether, unless, until

Noun clause – usually introduced by the conjunctions if, whether, that etc.

Examples are given below.

• She doesn’t know what she is doing. (Here the subordinate clause ‘what she is doing’ is the object of the verb know; hence, it is a subordinate noun clause.)
• Last week I visited a quaint village which is a long way away from the city. (Here the subordinate clause ‘which is a long way away from the city’ gives additional information about the noun village. Hence, it is an adjective clause.)
• Do you know anybody who can speak six languages? (Here the clause who can speak six languages gives additional information about the pronoun anybody. Hence, it is an adjective clause.)
• While he is rich, his brother is struggling to get by. (Here the subordinate clause while he is rich contrasts with the idea expressed in the main clause. Hence, it is an adverb clause.)
• I don’t know where my cat has suddenly disappeared. (Here the subordinate clause where my cat has suddenly disappeared is the object of the verb know.)
• Where she has gone is a mystery. (Here the subordinate clause where she has gone is the subject of the verb is; hence, it is a noun clause.)

A main clause is any clause that can stand alone. A subordinate clause cannot stand alone. It has to be attached to a main clause.

• I know a man who sells balloons on the beach.

Here the clause I know a man makes complete sentence and can stand alone. Hence, it is an independent clause. By contrast the clause who sells balloons on the beach does not make complete sentence. It cannot stand alone. Hence, it is a subordinate clause.