Discussion Groups / ESL Teaching / February 2005

The use of the subjunctive is, unfortunely, not as well covered in
contemporary EFL teaching materials as it once was. The reason is that,
for communicative purposes, the form does not carry a lot of important
meaning a speaker or listener can't cope without. Valuable teaching
time is therefore devoted to other, more functionally important grammar
topics. However, one of the downsides of this is that advanced students
often run up against strange subjunctive usages and do not know what
they are. A book like _Practical English Usage_ by Michael Swan, Oxford
University Press, which is now in its second edition, can go a long way
in helping you understand this sort of advanced English usage, Meng-Ju.

Your rule that we generally use past tenses with untrue statements is a
simplified rule of thumb that you learned or intuited somewhere in your
language acquisition process. It has served its purpose and should best
be discarded. I would guess much of it comes from when you first did
mixed conditionals. Typically, lesson plans straight out of teacher's
books call for the instructor's putting up a blanket statement on the
board when first covering this phenomenon in a full-length lesson,
something that says "Possible/Real = Present, Impossible/Hypothetical =
Past."

I would be very much like to know if I am right on this educated guess.
Best of luck!