"Usual" vs "than is usual"

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

Hi everybody,

  1. “Her dress reveals her body to be seen than is usual.”
  2. “Her dress reveals her body to be seen than usual.”
    What is the difference in meaning between the above two sentences?
    How is the 1st sentence grammatically correct?
    For “is”, which one is the subject?
    Could you please enlighten me more.
    Thanks,
    Er.S.M.M.Hanifa
2

Sorry, but neither sentence holds any meaning, Hanifasmm. Here is what should be written:

  1. Her dress (reveals more of her body / permits more of her body to be seen) than is usual.
  2. Her dress (reveals more of her body / permits more of her body to be seen) than usual.

There is no difference in meaning. #2 is the usual structure.

3

Mister Micawber,

  1. Her dress reveals her body [to be seen] than usual.
  2. Her dress reveals her body than usual.
    How is the number - 1 sentence wrong?
    Could you please explain to me with its relevant grammar?
  3. Her dress reveals her body than is usual.
    No: 3 sentence carries the auxiliary verb ‘is’.
    What is the subject for that auxiliary verb ‘is’?
    Since I come across this sentence for the first time,
    I can’t understand the merit of its grammar.
    Could you please be kind enough to educate me?
    Thanks in advance,
    Er.S.M.M.Hanifa
4

None of those work.

The basic English comparative structures are:

More…than
Less/fewer…than
As…as

The grammatical structure here is ‘V + (more + adverb) / (more of + noun object) + than’:

I eat more slowly than usual.
I saw more of those birds than usual.

5

Mister Micawber,

  1. Her dress reveals more of her body than usual.
  2. Her dress reveals more of her body than is usual.
    I admit that 1st sentence satisfies your formula.
    What about the second sentence? Is it wrong?
    If it is O.K.,
    what is the subject for that auxiliary verb ‘is’?
    Could you please answer me?
    I am awaiting your esteemed reply.
    Thanks,
    Er.S.M.M.Hanifa
6

Now your #1 and #2 are good, and their meanings are the same.

‘Is’ is not an auxiliary verb; it is the linking verb. I agree that the structure is rather odd, and it may be idiomatic. It seems to me to be a shortened form of this:

Her dress reveals more of her body than [it] is usual [to reveal].

7

Mister Micawber,
Thanks.
Very nice explanation!
Thanks once again.
Er.S.M.M.Hanifa