so warm a day

English as a Second Language English Vocabulary, Grammar and Idioms
1

It is so warm a day that I get a lot of sweating.
It is a so warm day that I get a lot of sweating.
It is so warm day that I get a lot of sweating.
Out of three which one is correct?
Please explain the grammar involved.

2

“So” usually cannot come after an article (“a/an/the”).

  • It is so warm a day: correct, but old fashioned.
    Your other two options are incorrect. This would sound most natural:
  • It is such a warm day.

In addition, “that I am sweating a lot” would sound better than your version. But I suppose it isn’t quite proper etiquette to talk about bodily fluids at all…