Vygotsky's work - an aspect of social constructivist theory - concerns what he called the zone of proximal development. This zone stands between the pupils current learning and the next level. Any teacher must be thinking about how the zone is to be crossed; how the learner is to move on. A central answer for Vygotsky involves language, especially talk. You literally translate new ideas into your own language, using your own example, as you read this, you might be thinking of an instance of coming across a new idea and restating it to yourself in your own word so that you understood it.