Arabic has many varieties and is spoken all over the Middle East. This study talks about one of the varieties of Arabic called North Mesopotamian Arabic, also known as Mosuli Arabic. Mosuli is spoken in the city of Mosul in the north of Iraq, and it is an understudied variety of Arabic, so studying it deeper would help linguists and documentary linguists understand more about the universality of human language. This study gives a descriptive analysis and discusses sentential negation in Mosuli Arabic. The research investigates different ways to negate verbs in present, past, and future tenses, as well as questions and imperative verbs. In addition, the negation of nominal sentences in the Mosuli dialect will be discussed. Furthermore, the negation of verbless phrases, or what is called nominal phrases, such as nouns, processive case, adjectives, and participles, is also discussed. Upon the dissemination of the collected data, it was found that Mosuli utilizes a number of negation particles, such as (ma:), for present, past, and future verb negation. The negation particle (la:) indicates a request from peers or advice, while the particle (ma:) is used to negate the imperative, indicating a command and an order. Additionally, Mosuli and the use of the negation marker (kl). Finally, the particle (wala) negates multiple verbs, such as nouns, adjectives, and prepositional phrases.