4. The development of the composite sentence
It is traditionally viewed that historically subordination (hypotaxis) as a kind of syntactical bond between clauses appears later on the basis of coordination. For OE it is not always easy to draw the line between the two phenomena. We often run into difficulties as we try to find out whether the clauses of a composite sentence are joined by means of coordination or subordination.
If we take, for e. g., such a composite sentence as: Ic wat t þu eart wlitih "I know that you are wonderful" and try to identify the function of the word "ðæt" , we at once face an alternative.
It may be a part of the 1 clause where it is a demonstrative pronoun and the sentence is a compound one.
It may be a conjunction introducing a subordinate object clause. The sentence then is complex.
Nevertheless already in OE there existed a rather distinct system of both compound and complex sentences which fall under classification and description.
4A. The compound sentence
The clauses of a compound sentence in OE are linked together by means of coordinative conjunctions, the most frequent of which are: and, ac (but), oþþe (or).
It is necessary to mention that very often the structure of the composite sentence on the whole is dependent on the requirements of style. Thus, in OE frequent repetition of the connective "and" is characteristic of the narrative style of chronicles.
The clauses of a compound sentence may be joined without any special conjunctions or conjunction words. Here the relations are expressed by intonation and by the lexical meaning of the words they consist of.
In ME and later in ENE with the appearance of new conjunctions and the use of the old ones for expressing new relations between clauses it became possible to specify these relations and to clarify the sentence structure.
The coordinative conjunctions: and, not only … but, neither … nor, or, either … or, otherwise, else, but, yet, still, for, therefore etc. are employed in ModE to express copulative, adversative, disjunctive and other types of relations between the clauses in a compound sentence.
On the other hand lexical meaning of the words is still an important factor in expressing semantic relations between the clauses.
4B. The complex sentence
There were different types of complex sentences in OE. Subordinative conjunctions were of major importance in making a variety of syntactical relations between the principle and the subordinate clauses possible.
As an additional means signalizing interdependence of the clauses there should be mentioned the use of the subjunctive mood in indirect discourse in order to form different types og subordinate object clauses, and also resultative, conditional and other clauses.
The subordinate subject clause is introduced by the conjunctions t, hif, hwþer e.g. ā ws fter monehum dahum, þt þe cyninh cōm tō þām eālode "it was after many days, that the king came to that island".
The subordinate object clause is found in OE texts most often. It usually depends upon such verbs as sechan (say), cwean (speak), þyncan (think), witan (know) etc. Subordinate object clauses are introduced by such conjunctions as: t, hif, hwþer, also by conjunctive pronouns and adverbs: hwā, hwt, hwilc, hū, hwær, hwider etc.
Subordinate attributive clauses are introduced in OE by the relative particle ”þe”, also by a combination of ”þe” + a demonstrative pronoun: sē, sēþe, þtþe, seoþe.
Attributive clauses introduced by the particle ”þe” are mostly of a limiting character, by the demonstrative pronoun "sē" – of descriptive character.
Among subordinate adverbial clauses those of time, place, cause, result, purpose, condition, concession are most common in OE.
Correlation
The OE complex sentence reveals traits which attest to a lack of accuracy in the means of subordination. Correlation must also be mentioned as a traditional construction from parataxis to hypotaxis. It is a wide-spread phenomenon in complex sentences with subordinate adverbial and object clauses. In adverbial clauses of time, for example, subordinate conjunctions “þā, þonne, hwanne, siþþan” etc. often correlate with the adverbs “þa” or “þonne” in the main clause.
The conjunction "t" introducing a subordinate object clause may be correlated with the demonstrative pronoun "t" or personal pronoun "hit" functioning as objects in the main clause: e.g. Ne wicwee ic þām nānwiht t þu swā dō "I am not at all against that that you should do so".
Asyndetic subordination is not frequent in OE, (example p.117) and it is treated in the same way as correlation, pleonastic use of pronouns, shifting from indirect to direct discourse, whish testify to immaturity of formal expression in the sphere of subordination.
Middle English
Although the ME complex sentence preserved many features inherited from OE which illustrated incomplete subordination, at the same time it aquired new properties attesting to the gradual elaboration of subordinate clauses. The development of hypotaxis was largely predetermined by the emergence of the national language and the rise of the written standard.
Correlation in ME still occurs, but comparing with OE, it diminished, because it's nature appears to be different from what it used to be. The correlated elements in the main and the subordinate clauses often do not coincide in form: e.g. Auh forgif hit me nu, þet ich hit habbe itold te "forgive me it that I have told you about it".
Scholars presume that such a correlation was a step made towards its total abandonment as a means reinforcing the subordinative conjunction. In ModE correlation would appear redundant at all, except for its stylistic value: e.g. he wondered more whether she could see his eagerness to get back to that which she had brought him away from. He the emphasis is achieved by putting "that" in the main clause.
The system of connectives in ME and later on underwent a number of changes too. Some of OE conjunctions fell into disuse: e.g. oþ þa (до того як), mid þam (з тим, щоб). Some connectives became specialized as indicators of new relationships. For example, OE temporal conjunction "sith" (з тих пір) began to express causal relationships as well. And, finally, a great number of new connectives came into being: e.g. save, except, in case, because, till, before etc.
The appearance of relative pronouns from interrogatives “whō, what, whōs, whōm” (14th century) and the differentiation of "that, who, which" in their functions by the 18th century made it possible to indicate various kinds structural and semantic relationships in the complex sentence with subordinate attributive clauses.
EarlyNE
The means of expressing subordination are growing more stabilized. In certain types of subordinate clause, first of all in object and adverbial clauses of purpose, the tense form becomes dependent on the tense of the predicate-verb in the main clause. This phenomenon, termed "sequence of tense" is considered now one of the means of expressing subordination.