My prolonged work (and publications) in mathematics education and my primary lifetime university teaching in two forms (1983–1997 in the UK and 1998–2022 in North America) have frequently interrelated. The first form mostly involved writing and editing courses (mathematics education, mathematics and history of mathematics), as well as making audios and videos for adult students (spending 15 years at the UK Open University). The second form was in the US (2 years) and then Canada (23 years) and was more conventional mathematics education teaching (both undergraduate and graduate students in mathematics education, increasingly more the latter). With regard to research publications, one central focus of mine throughout has been language in regard to mathematics (though never accepting mathematics as a language, although it is fairly often called one) and, in particular, the English mathematics register (including aspects of metaphor in regard to it). This chapter will engage with a variety of elements around this notion, including aspects of speech, writing and gestures in mathematics teaching contexts, as well as significant involvement of symbols and diagrams (and the latter’s dynamic development in computers). There are also aspects of development involving metaphor in mathematics and its pedagogy.