grammaticality - "He walks as if he is drunk." Grammatically correct ? Any difference in meaning from "...as if he were drunk."?

Is it grammatically correct to use an indicative verb after "as if", or "as though" for that matter?

I've heard someone say: "He walks as if he is drunk." Would there have been any difference if he had said "He walks as if he were drunk."?

A second example might be:

• It looks as if it is going to rain.


• It looks as if it were going to rain.

Answer

What I have found bears out @John Lawler's comment.

Many grammarians (mostly purists) insist that both "as if" and "as though" must be followed by a subjunctive, not by an indicative verb, since they put an imaginary case (as he would if he were, etc.) But do they? There is surely a distinction between "He walks as if he were drunk." (implying "but he is not") and "He walks as if he is drunk", meaning "He is drunk judging from the way he walks". Similarly we have "It looks as if it is going to rain." (= It is going to rain, by the look of it), "It looks as if we will have to do the work ourselves". For these the indicative seems justifiable. https://openlibrary.org/books/OL14999310M/Current_English_usage.

Therefore, one would probably say "It looks as if it is going to rain" when the weather looks like that, but he could say either "as if he is drunk" or "as if he were drunk", depending on his degree of certainty.