Baffles me none of the questions is even related to learning Khmer OP, at least on the first page. The categories of answers you chose are sometimes not logical. For instance 'more then 3 hours a week' and 'less than one hour day' overlap - answers in multiple choice questions should exclude.

What info useful for designing your app are you hoping this questionnaire is going to provide you with?

Good luck with your project. Seems there's a small market for it. If i were you I would make an app for Cambodian children in grade 1 / 2 learning the alphabet and simple words. Much bigger and much more sustainable market, and could also be used by foreigners if you make the interface bi-lingual.