as if!so anyway, as requested, a brief note follows on "as if" and "as though".
there is nothing to be dogmatic about here. usage is fluid. but the careful may distinguish "as if" and "as though" as follows.
obviously, use "as if!" when you want to express incredulity. no other phrase does it so effectively.
the key difference between "as if" and "as though" would seem to be that the former is generally used to described impossible states, the latter to describe possible, but not actual, states.
"She spoke to me as if I were a child."
"She spoke to me as though she was drunk."
easy. or is it?
the latter is often rendered by "like" in spoken English, but using "like" in even slightly formal contexts, which would include nearly all writing, would be a terrible solecism, making you prey to pedants, who would feast on your carcass as if you were a boiled chicken.
notice that the last part of that sentence is a bit awkward. you could and probably should use "as though" there, even though it's not possible for you to be a chicken, because "as though" does not have quite the restricted use that i suggested. it is used for comparisons of states, to create similes between them. one state is always, i think, what you might call the indicative state -- how things are -- and the other is the state compared to. "as if" can do similar work, but its "subjunctive" state -- if we can call it that -- must be impossible.
in constructions such as "as if i could do that!", which express impossibility, "as though" is entirely incorrect. however, "he looked at me as though i could do it" would be correct, because you are describing how he is looking at you in terms of a state that doesn't pertain but that you claim to be similar. "As if" would be entirely wrong here.
i hope that hasn't muddied the waters of these terms too much. as if your old buddy dr zen would do that, eh!