The study combines two topics of grammar, namely: (deuteronomy and addition), and not every duality, nor is it every addition, but rather it is the addition of the contained parts to each other if they are dual, and the idea of research is based on the issue of the additive if it is multiple, and the additive is to him including it, whether the addition is in the wording or in the sense, the one who chooses in the additive the face of the plural on its own, or to bring it in two, we say, for example: I cut off the head of the two rams or the heads of the two rams, or the heads of the two rams, and this is permissible in every such installation, and did not The position of scholars on this issue is not the same, rather it is part of the grammatical dispute between the two poles of the grammatical lesson (Kufa-Basra), and this is undoubtedly affected by the curriculum of each school and the way it sets the rules.