Arabic grammar is considered as one of the greatest Arabic sciences, its originality, the widest material, and its richest heritage. There is no doubt that the early founders of this science wanted to protect the Arabic language from melody and error .The Arabic grammar passed in the first Hijri centuries in various stages of construction and foundation. During this period, the ways of thinking of grammar scholars varied, and they gave us a number of opinions about different issues of grammar.
This study focuses on highlighting the grammatical thought of Milanese. Perhaps the most remarkable feature of it is the merging between the theoretical and scientific variables in the study and analysis of the grammatical thought of Milanese.
The research talked about the origins of grammar, the most important of these principles is the hearing and analogy, and It is known that these two origins are agreed upon, while there are different principles on them, such as consensus, Al-Sahaba and inference after analogues, and the inference that there is no evidence in the thing for its negation, extrapolation and approval.In this research, we try to confine ourselves to talk about the fundamentals of grammar contained in the commentary of al-Mughni in grammar by Al-Milani, since this research was divided into two topics.