As children learn more about language, they use it more effectively to achieve their conversational goals. They choose appropriate speech acts, establish joint attention, contribute new information, take up information from others, and take turns. They learn how to enter an exchange among others from as young as age two. Their intrusions in ongoing exchanges typically contain new information. Planning an utterance takes time, and children learn to plan what to say so as to take turns on time. This can be tracked in their answers to yes/no and wh- questions, where they get faster with age. They plan pretend play, assigning roles, assigning actions, and also utterances for each character enacted. They track common ground and design referring expressions for their addressees, and they repeat new words to mark uptake. They distinguish requests from offers, and, on occasion, persist in making repeated requests themselves. They clarify what they mean when asked and offer spontaneous repairs as well. In all this, they track what the others in the exchange say and choose when to enter the exchange themselves.

This final chapter examines some critical questions and possible objections, provides further clarifications and reviews some of the main themes developed in earlier chapters.