Although supported by different ideologies of language, code-switching and translanguaging are, surprisingly perhaps, united in some of the claims made in their names. In the literature on classroom practices, one shared claim is that content is simplified for students when the teacher uses features enregistered as the non-official classroom language/s in a way that overlaps with and/or complements features enregistered as the official classroom language. Functional allocation of languages/features, a corollary of this claim, arguably interpellates what may be termed "diglossic cognition. The problem with this diglossic cognition is that it is largely knowledge-blind and equates cognition" with the mere use of particular languages or features. This study finds that there are both language and knowledge variables in teacher multilingual-talk that explain students' enhanced cognition, and, therefore, invites a rethink of the unnuanced connections made between language (feature) choice and cognition.