In this dissertation, I draw on comparative studies of English to establish a framework for looking at how Portuguese studies and teaching are shaped by political economies, cultural hierarchies, and educational institutions in Brazil and Cape Verde. I examine how English and Portuguese are constructed as world languages and how English and Portuguese rhetorics shape language teaching. People who are locally engaged contest these global constructions. As a result, diverse people construct world languages by adopting, adapting, resist, and transforming it in specific locations (Pennycook). First, I identify compositionists in the U.S. with what I call a rhetoric of multilingualism in which teachers of English should view English in relation to other Englishes and other languages. Secondly, I examine how the transnational organization for Portuguese-speaking countries perpetrates lusotropicalism--Gilberto Freyre's social theory of the Portuguese exceptionality to create a hybrid culture in the tropics. Despite fostering adaptability to local cultures, peoples, and languages, Freyre's lusotropical rhetoric eschews diversity by maintaining that a culture and a language should promote homogeneity. Then, I analyze the linguistic contexts, educational policies, and data gathered from questionnaires and interviews with language teachers in Brazil and Cape Verde. In light of higher education expansion and the maintenance of excellence, I argue that language teachers should promote the writing of Portuguese as a rhetorical construction in which grammar and mechanical correctness is only one aspect of writing instruction. Lastly, I propose the use of code meshing as a pedagogical strategy in academic discourse because it values language in its diversity and its relation to other languages. I argue that students' multilingual strategies deserve a place in academic writing. The rhetorical construction of language in academia could also become multilingual--globally networked and locally engaged. This study contributes to the internationalist discussions about how to teach writing in different languages and educational contexts.