The Complex Sentence

Within a complex sentence clauses are joined by means of subordination, thus forming a complex sentence. Subordination is a way of linking grammatical elements that makes one of them dependent upon the other. Subordination is usually defined as a non-symmetrical relation, that is, in a complex sentence with a minimal composition of two clauses, one is the basic element, whereas the other is a constituent or part of the first. The first one is called the main (or principal) clause, the second is the subordinate clause.

Complex sentences can be formed by joining subordinate clauses to the main clause with conjunctions or conjunctive words (syndetically) or without them (asyndetically):

You can call yourself an extreme sports enthusiast (main clause) if (conjunction) you ski off cliffs (subordinate clause).

Sometimes I wish (main clause) life had subtitles (subordinate clause).

Conjunctions are the formal signals of subordination the only function of which is to link clauses and express the relation between them (that, because, through, in order that, as far as, if only, etc.):

Everybody knows that money doesn’t grow on trees.

Conjunctive words which are used to join nominal clauses combine two functions: to link clauses and to be a part in the subordinate clause (who, what, when, why, where, etc.):

Do you realize how far it is to Hawaii?

Subordinate clauses function as different parts of the sentence (subject, predicative, object, apposition, attribute, adverbial modifier). Subordinate clauses can be classified under three headings: a) nominal (or noun) clauses (clauses functioning as nouns in various syntactical positions); b) attributive (or relative) clauses; c) adverbial clauses.