Let's take this passage from "For whom the bell tolls" as an example:
They make love and go to sleep, but in the middle of the night Jordan wakes up in a panic and clutches Maria close to him. He feels as if she were all he has of life, and even that will soon be taken away from him.
Here the author narrates in the present tense. Hence as if she were is justifiable. But if the narration had been in the past tense, must the author have changed as if she were to as if she had been? ("He felt as if she had been all he has of life…")
I expect you say that it is a book, so the author must. But in a colloquial speech is it common not to make this shift?
Best Answer
Reading the sentence aloud (always helps) led me to conclusion that you wouldn't change the phrase for the past tense.
'As if she were is an example of the imperfect subjunctive; she isn't all there is to his life, but the context considers the hypothetical possibility of it, so we stick that tense in there.
Regardless of which tense you're writing in, the imperfect subjunctive is still the imperfect subjunctive. The perfect tense doesn't work as a replacement in this case.