Every student should practise self-study regularly. (Negative)

Self-study means learning something by yourself. (Interrogative) = Doesn't self-study mean learning something by yourself?

It helps you so that you can understand things at your own speed. (Simple) = It helps you to understand things at your own speed.

So, no other way of learning is so good as self-study. (Affirmative) = Self-study is the best way of learning.

By reading books, you can learn many things. (Complex) = If you read books, you can learn many things.

Self-study makes you more confident because you solve problems of your own. (Simple) = Self-study makes you confident because of solving problems of your own.

When you read alone, you can choose the area of your study. (Compound) = You read alone, and you can choose the area of your study.