face changes as if he has seen this before?

Question

1. John's face changes as if he has seen this before.

Here this could any thing (an object, a map, a place, a movie, etc).

Normally when you see something and if you feel as if you have seen this before, your facial expression changes reflecting that. I wrote the above sentence to describe it. Is it grammatically correct?

I checked google, I see many sentence for "as if he has seen this before" but I don't see any sentences matching "face changes as if * has seen this before" I feel like this is valid sentence and conveys the meaning. But I'm confused since there is no match in the google. That means this sentence is wrong? How?

Answer 1

John's face changes as if he has seen this before.

Yes, this is grammatically correct, or at least it is something that a native speaker might say. However, it would be more common in writing, but perhaps old-fashioned, to use a pluperfect here:

John's face changes as if he had seen this before.

This is an instance of a past subjunctive. To reduce confusion, consider a similar sentence where the action in the conditional clause does not take place in the past:

John's face changes as if he was not seeing this for the first time.

The use of a past subjunctive normally expresses a counterfactual statement. It is used here even though it is likely that the statement is true, because “as if” tends to call for a counterfactual statement.

If you want to express a visible change of expression and state without ambiguity that John has seen this before, and John's response is positive, you can say

John's face lights up in recognition.

If John's reaction is negative, you might say

John frowns in recognition.