Second language materials for young learners are often deceptive in their simplicity.They appear to be easy to create because their content spans a limited range of grammatical forms and vocabulary.However, beyond the challenging process of selecting such content are the underlying theoretical concepts, methodologies, and approaches that inform well-constructed learning materials.This article outlines considerations that go into creating a textbook series for young learners in terms of views of language learning, the communicative approach, a notional functional syllabus, comprehensible input and output, task chains, learner-centeredness, the negotiated curriculum, and autonomy.