(1) from A Grammar of Present-Day English, by Professors Pence and Emery:
Sometimes the article a (an) is placed immediately before a noun that
is modified by an adjective or an adjective that in turn is modified by an
many a man
such an expression
so great an ordeal
too sweeping a statement
(2) From Harper's English Grammar, by Dr. Opdycke, I learned that
we should say:
so sweet a story
too severe a strain
how excellent a view
The professor says that "a so sweet story," "a too severe strain," and
a how excellent view" are "grammatical," but he says that they sound
"awkward and ridiculous."
His main point:
Ear is the deciding factor in most such idioms.
(3) Thus, "Don't put the TV set in a too warm place" may
be grammatical, but it is definitely not idiomatic (that is, the
way native speakers have decided to use their language).
Student or Learner