How do we understand grammar?

A brief about the book The cultural and civilizational heritage, I have gotten rid of the people's container about their language, or they got to know it through one of its means, or for some reason; since part of their identity, their heritage conditions that long scientific efforts have been made since its history, and studying grammar has become one of the heaviest burdens! It represents an obstacle starting from its teaching in schools, until the student reaches in his scientific life. This is due to multiple reasons, there is no need to discuss them here, but all are summarized in the method of explaining and clarifying grammar. And this is what prompted me to write this book; I am making a special effort among all that has a special relation with grammar, and I try to reintroduce it in easy ways.