The tension between considering language acquisition to be a process of learning or a process of development is the visible surface of a theoretical iceberg. The difference between learning and development is neither simple nor self-evident, yet the implications that follow from a commitment to one or the other are considerable. Development is usually construed as an unfolding, the impassive evolution of “being.” Children develop physically, cognitively, emotionally almost in spite of themselves; they may not develop to their full potential, and they may require massive environmental support, but even in cases of benign neglect, children will normally become taller, smarter, and more stable. Learning implies a measure of control and responsibility. It depends on experience and on the availability of resources: conceptual, social, intellectual, and so on.