This reference grammar of Gidar, spoken in the Northern Province of Cameroon by some 40.000 people, contains hypotheses on the forms and functions of its linguistic structures and supporting argumentation and evidence. The language belongs to the Central Branch of Chadic languages, but its phonology, morphology, and syntax differ significantly from those of related Chadic languages and include rare or hitherto unobserved phenomena. Gidar has fronting and rounding long distance vowel assimilations that operate to the left and the right of the triggering vowel. Some prepositional phrases are incorporated within the verbal piece framed by aspectual markers. There are two tense and aspectual systems. The focus on the verb requires the formation of a special phrase whose head is an infinitive form of the verb with its object.