This article reports on the initial observation phase of a larger, longitudinal project that explores complex language encounters in grades R (Reception) to 3 classrooms in South Africa. Complex language encounters refer to teacher-learner exchanges that take place when neither teachers nor learners are first language speakers of the language of instruction, in this case English. Observations during teaching practice visits to linguistically and culturally diverse South African urban classrooms yielded several vignettes that illustrate the need for teachers to be provided with strategies to lessen the confusion of some language encounters. Although preliminary, our findings underline how critical it is for teachers to possess full proficiency in the language of instruction as well as cross-cultural competence. That is, in order to attend adequately to diverse learners’ sense-making efforts, teachers need to know how to relate to learners by ‘border crossing’ linguistically, culturally and conceptually.