There are two principal types of composite sentences: complex and compound. In compound sentences, the clauses are connected on the basis of coordinative connections; by coordination the clauses are arranged as units of syntactically equal rank,i.e. equipotently. In complex sentences, the clauses are united on the basis of subordinative connections; by subordination the clauses are arranged as units of syntactically unequal rank, one of which dominates another. In terms of the positional structure of the sentence; this means that by subordination one of the clauses is placed in a notional position of the other.
The connections between the clauses in a composite sentence may be effected syndetically, i.e. by means of special connecting words, conjunctions and other conjunctional words or word-combinations, or asyndetically, i.e. without any conjunctional words used.
Alongside the two basic types of composite sentences there is one more type of polypredicative construction, in which the connections between the clauses are rather loose, syntactically detached: the following clause is like an afterthought, an expansion or a comment to the proceeding clause. In oral speech its formal sign is often the tone of sentential completion, followed by a shorter pause than the usual pause between separate sentences. In written speech such clauses are usually separated by semi-final punctuation marks : a dash, a colon, a semi-colon, or brackets, e.g.: I wasn`t going to leave; I`d only just arrived. This type of connection is called cumulative. The status of cumulative sentences