This article looks at two different primary EFL classrooms: one in which the teacher is a general-subject teacher who teaches different subjects to the same group children and another in which the teacher is an EFL specialist who teaches the same subject to different groups of children. First we qualitatively characterize the differences in discourse, checking quantitatively to see if they hold true for the whole lesson. Second, we report on a three-year comparative study in which the same teacher taught the same material to both familiar and unfamiliar classes. Third, we suggest that the construction of the zone of proximal development (Vygotsky, 1978, p. 86) requires a rather different strategy in primary-school teaching than with secondary learners. Good primary discourse, we argue, may be less like a professional baseball pitcher's throw and more like a lazy game of Catch.