Her first clear word was water. Not mama or dada, which she had been producing in various configurations for months but with a flexibility of application that suggested they were more general labels than specific ones. Water was precise. She said it when she wanted water and only then, and she said it clearly and with the assurance of someone who had been planning to say it correctly for some time. The second word was no, which she deployed with great range and creativity from the first day. The third word was mine. "She has your vocabulary priorities," Marcus said. "She has both of ours," I said. "She knows what she needs, she knows her limits, and she knows what belongs to her." By eighteen months she had thirty words. By twenty months she had what the pediatrician called an advanc

