Since Arabic is the language of the Qur'ān, it is the mother tongue of religion and religious sciences. It is an important tool that helps us to understand the concept and purpose. Everyone interested in basic Islamic sciences should know this language and its rules very well. This situation brought with it the aim to learn Arabic in all its aspects. From the past to the present, a lot of work have been accomodated, and the research have been conducted about the Arabic language and its grammar. Al-Zamakhsharī (d. 538/1144) is one of the scholars who studied and wrote on the subject. His works, al-Mufassal fī tārīkh al-'Arab qabla al-Islām, and al-Unmuzaj, which he wrote on the science of nahw, are famous. There is also a treatise named al-Mufrad wa-ʼal-muʼallaf fī ʼal-naḥw, written by him for students who have just started in this science. This book differs from his other books in terms of its content and the method it follows. The author mentioned that he wrote this treatise for the people of Mecca, and that while he was writing the book, he aimed to bring a record to the words whose rules are unknown, to clarify the closed points in the Arabic language, and to explain the parts that are hard to understand. While writing this treatise, Al-Zamakhsharī examined the subjects under two main headings. The first of them is Mufrad (singular words). Under this heading, Mufrad words (noun, verb, letter) are examined in terms of their parts, sub-headings, and their grammatic rules. The second main topic is Mu'allaf. This topic is about Murakkab (compound) words that consist of mufrad words. The lexical meaning of "mu'allaf" is; brought together, linked together, associated, and connected. Al-Zamakhsharī used the word "mu'allaf" for words and word groups that have a connection between them. As a matter of fact, he listed nine types of word connections and explained them by building a relationship depending on the meanings. Al-Mufrad wa-ʼal-muʼallaf is a work that only a few studies made on it. This research is made to fill this gap by examining the work in terms of Arabic Language grammar. In this paper, after a brief information about the author is given, the method he followed while writing the work in question, the content of the work, and the points that differ from other works are mentioned. The method followed by the author in the work is not a method that is frequently encountered in other works in the science of nahw. In this respect, the author has presented a different study among the other grammar treatises by referring to some background knowledge of the reasons and meanings of grammar rules while teaching grammar with his own system. In our study, we will try to present this method followed by the author by citing sample texts from the book.