Is this mobile slide menu user-friendly?

I am creating a Learn Norwegian language app for both iOS and Android. The app consists of 4 chapters, each chapter has a sub category, for example, Pronunciation, Exercise, Grammar etc.

My problem is the sliding menu's sub-menu. I'm not sure if I've used it in the correct way.

My menu

Image displaying app's navigation flow

On the main menu you have chapters 1 - 4. When i click on chapter 2's arrow, you get the sub-menu. You can select items from the sub-menu; if I click Ben I will go directly to the Ben page.

On the main sliding menu, when i click on Chapter 2 (not the arrow) I should go to chapter 2's Home page. Is this part correct?

I would like my app to be user friendly and I am worried that it might be confusing to the user. Is this the correct way to do this?

Any advice or suggestions would be appreciated. Thanks in advance.

Tags: