In OEthe word order was free as far as there were a lot of inflections that showed the relations between the words in a sentence.
Most common word-order patterns were:
1. S + P + O(in non-dependent clauses);
2. S + O + P(when the Object was a pronoun, e.g. OE Ic þe secζe – literally “to you say”);
(in dependent clauses, e.g. OE þis wæs ζefohten siþþan hē of Ēāst Enþlum cōm – literally “This battle was held when he from eastern England came” – such word order was called “frame” –after a connective went the Subject, it was followed by all the other parts of the sentence and the last place was occupied by the Predicate which thus created a frame together with the Subject);
3. P + S + O(in questions, e.g. OE Hwat sceal ic sinζan – “What shall I sing?”);
(in sentences starting with adverbial modifier, e.g. OE Nū synt ζeþrēāde þeζnas mīne – literally “Now were threatened my servants”).
In MEand NE, due to the loss of the Cases and, as a result, loss of the inflections the distinction between the Subject and the Object of a sentence was lost. Thus the word order became fixed and direct (S + P + O – The Subject almost always took the first place and was followed by the Object).
Such word order led to the appearance of the formal Subject (formal it, there, e.g. It was winter; There is a book.) that took the place of the Subject if a sentence did not have one and thus preserved the direct word order.
Inversion was used only in questions and for emphasis.