The Subjunctive Mood is used in predicative clauses:

#1. introduced by the conjunctions, as if, as though, when we find the link verbs to be, to feel, to look, to seem, in the principal clause.

If the action of the subordinate clause is simultaneous with that of the principal clause the Past Subjunctive of the verb to be is used; with other verbs, the same meaning is expressed by the Past Indefinite of the Indicative Mood.

If the action of the subordinate, clause is prior to that of the principal clause the Past Perfect of the Indicative Mood is used.

I feel as if we were back seven years, Jon. (Galsworthy)

…now I feel as if you had never been away. (Shaw)

Не looked as if he knew it to be true. (Austen)

The house looked as though it had been deserted for weeks. (Wells)

It was as if she were angry with him. (Lawrence).

Karel felt a bitter taste in his mouth. It was as if he had done something wrong. (Heym)

#2. when the subject of the principal clause is expressed by an abstract noun such as wish, suggestion, aim, or idea. In this case, the analytical subjunctive with the mood auxiliary should (for all persons) is used:

Mary’s wish was that… our mother should come and live with her.(A. Bronte)

…his arrangement with them had been that they should meet him at Plymouth. (Hardy)

One of the conditions was that I should go abroad. (Swinnerton)