If the people of the world diﬀer in how they think as well as in how they speak, what does this mean for the teaching of second and foreign languages? The topic of linguistic relativity has been barely broached in language teaching yet it raises crucial issues concerning what language teaching is actually about, most of which are still necessarily speculative. This chapter starts by discussing various alternative relationships between linguistic relativity and teaching, in particular whether second language (L2) users are diﬀerent from monolingual native speakers. These are then related to the main areas of language teaching, namely goals, syllabuses, methods, and examinations; these can only be sketched here as they are complex areas of education in their own right; a fuller account can be found in Cook (2008). As always, one has to be careful not to accept the simplistic discourse of language-teaching methodologies as necessarily reﬂecting more than a fraction of the complex realities of languageteaching classrooms (Swan, 2009): What methodologists suggest is often far removed from what actually happens in the class.