Now we have a subordinate clause, if we are united, which is used to modify the verb of the main clause, succeed. We have used the subordinate conjunction if, and so we have a complex sentence formed by uniting the principal clause and a dependent clause.

442. The next step in sentence building, after the simple sentence, is the complex sentence. A complex sentence is a combination of two or more simple sentences, which are so united that one sentence remains the main sentence—the backbone, as it were—and the other sentence becomes subordinate or dependent upon it.

443. A complex sentence is one containing a principal clause and one or more subordinate clauses.

A principal clause is one which makes a complete statement without the help of any other clause or clauses.

A subordinate or dependent clause is one which makes a statement dependent upon or modifying some word or words in the principal clause.

KINDS OF DEPENDENT CLAUSES

444. Dependent clauses are of three kinds. They may be used either as nouns, adjectives or adverbs, and so are called noun clauses, adjective clauses or adverb clauses.

NOUN CLAUSES

445. Noun clauses are those which are used in place of a noun. They may be used in any way in which a noun may be used, except as a possessive.