Drawing on the notion of translanguaging, I show how learners in a Black township secondary school in Cape Town use their multilingual repertoire to achieve power, agency and voice. I use the conceptualisation of the prototypical pedagogical macrogenre from systemic functional linguistics to show how translanguaging can be used strategically to actualise regulative and instructional registers to engender teaching and learning in multilingual contexts, and to illustrate that the often-assumed "chaos" in translanguaged discourse can be harnessed to engender pedagogic discourse. I demonstrate that by using the extended linguistic repertoire, learners do not need to be competent in monoglot English to be involved in classroom interactions and learning, as the Xhosa-English translanguaged discourses provide the co(n)texts on which the "standard" English texts are consumed and produced. The article concludes with a thesis for language education policy that puts translanguaging at the centre of classroom practice in multilingual South Africa: it provides a new avenue for postcolonial learning/teaching, as it frames the learners' cognition of content and ability to construct meaningful texts in familiar cultural and sociolinguistic contexts.