G double sharp is a very clumsy way of saying (enharmonically) "A natural".
The enharmonic equivalent to A-flat is G-sharp; The enharmonic equivalent to G-flat is F-sharp.
A flat. Because this note is between G and A, you can go up from G (make it a sharp) or down from A.
The enharmonic of E-sharp is F-natural.
A sharp.
D-flat
A double sharp is the enharmonic of B nature
The equivalent of an f sharp is a G flat.
F sharp is the enharmonic.
F sharp is the enharmonic.
No. It would be F#X or Bb bb. (F sharp double-sharp or B flat double-flat.)
The enharmonic equivalent to A-flat is G-sharp; The enharmonic equivalent to G-flat is F-sharp.
A flat
Being that it's a whole-step away from another sharp or flat note in both directions, there is no possible double-sharp/flat spelling for it.
X is a double sharp, X G (G double sharp) for example would be the enharmonic equivalent of A. If the "ball" of the note on the music is replaced by an x, then that would mean to "ghost the note."
E natural
Yes.
It's because that note is the only one two half-steps away from another flat/sharp note in both directions.