The prevalence of English monolingualism in the current sociopolitical public has well been documented in the field of educational linguistics. In the United States, the monolingual underpinnings of educational policies have been criticized extensively for putting language minority (LM) students at a disadvantage. An important consequence of such policies is that teachers, who are in the position to enact them, could internalize the covert ideological underpinnings, and in turn, engage in the reproduction of unequal power structure through teaching and discursive practices. Drawing on Critical Discourse Analysis and Systemic Functional Linguistics, this study examines the teacher discourse produced in an online forum and explores how they talk about language, monolingualism, and multilingualism. Adopting Van Leeuwen's [2008. "Discourse and Practice: New Tools for Critical Discourse Analysis." Oxford University Press] categorization of legitimation strategies, the analysis illustrates some prevalent ways in which (de)legitimation strategies are used to reinforce marginalization of LM students. Also, the study shows examples of counter discourse among those who advocate for more bi/multilingual and inclusive ways to work with LM students. The paper further discusses the role of teachers' discursive practices in reproducing and maintaining predominant monolingual ideologies and practices.