According to the degree of self-dependence of clauses complex sentences are divided into monolythic and segregative sentence structures. Monolythic complex sentences are based on obligatory subordinative connections of clauses, whereas segregative complex sentences are based on optional subordinative connections.
Monolythic complex sentences:
1) merger complex sentences, i.e. sentences with subject and predicative subordinate clauses, where the subordinate clause is fused with the principal one.
E.g. The trouble is we are to change our plans.
2) valency monolyth complexes, whose subordinate clauses are dependent on the obligatory right-hand valency of the verb in the principal clause. Here belong sentences with object clauses and valency-determined adverbial clauses.
E.g. I think a man like that is a real artist. – I think -…
e.g. Put the book where it belongs. – Put the book - …
3) correlation monolyth complexes, which are based on subordinate correlations. Complex sentences with restrictive subordinate clauses are included into this subtype.
E.g. The girl played the piano with such feeling as you had never experienced.
4) arrangement monolyth complexes, whose obligatory connection between the principal and subordinate clauses is determined only by the linear order of clausal positions.
E.g. If you refused her present, it would upset her.