The present work has as end, to understand as if it defines the semantics and the grammar in the didactic book having as study object the Portuguese book and Languages of William Robert Cherry, Thereza Cochar Magalhes. To understand as the conjunctions and the semantics if they present in the exercise considered. Words keys: Semantics, Grammar, Didactic Book. Introduction the studies of the language very has advanced in the last times in the s diverse institutions of education spread by the country, what it has taken many researchers and educators to search the subject. In used didactic books in the education of the Portuguese language in Brazil, we can observe that the majority looks for to diferenar education with form examples that the reader is taken to a more efficient learning. In this article I look for to understand as to the semantic values the Portuguese didactic book and Language of Willian authors are worked in Robert Cherry Thereza Cochar Magalhes, in exercise 04 of page 46 where if it presents of the following form: 4) – I announce In it to follow, in the reminder that makes warning against the use of the tobacco, forbore it integrant conjunction: The Health department warns: (that) to smoke the health is harmful badly the health the omission of the conjunction becomes the fast message most direct and. It sees: The Health department warns: (…) to smoke the health is harmful badly the health According to Cereja and Magalhes (1999, p.46) in the written language, for reason of expressividade, clarity and concision, must, whenever possible, to prevent the repetition of the conjunction that. In the case of the job of the subordinated conjuncts substantive, we make use of the resources to substitute the verb for a substantive or to transform the developed conjunct into a reduced substantive conjunct.