its just a printing error if i see the right hand in C major and the left hand in G major suddenly without a modulation, right? or is that possible?

geez im waay to lazy to research this stuff.

Can you be a little more specific? I'm not sure if you mean a modulation that shows with a # sign in the left-hand part, or if you mean the notes in the left-hand part resemble a G Major scale.

Do you have F sharp in the left and f natural in the right? What piece is this?