question about turns..

I watched andrew video, but i still i don't get it very well about the turn. I'm practicing PRELUDE IN E MINOR (Chopin and there it's a part that seems to be one, but i don't know what do..



And just as a plus what's stretto?

Wow your edition of the piece is not good... The stretto sign should be above the staff, start earlier, and be followed by a line for about 3 bars (by the way stretto is a sort of accelerando, with more tension).
At that, the "turn" sign is incomplete too, as there should be a double sharp below it (x).

The right hand has to be played: B, A# A#, [BA#GxA#] G etc. (the section in bracked is the turn) Gx is G double sharp (i.e. the same key as an A).


Good luck with this piece!

Matthieu