Young children learn language at an incredible rate. Although children come prepared with powerful statistical-learning mechanisms, the statistics they encounter are also prepared for them: Children learn from caregivers motivated to communicate with them. How precisely do parents tune their speech to their children’s individual language knowledge? To answer this question, we asked parent–child pairs (N = 41) to play a reference game in which the parents’ goal was to guide their child to select a target animal from a set of three. Parents fine-tuned their referring expressions to their children’s knowledge at the lexical level, producing more informative references for animals they thought their children did not know. Further, parents learned about their children’s knowledge over the course of the game and tuned their referring expressions accordingly. Child-directed speech may thus support children’s learning not because it is uniformly simplified but because it is tuned to individual children’s language development.

幼儿以惊人的速度学习语言。虽然孩子们已经准备好强大的统计学习机制，但他们遇到的统计数据也是为他们准备的：孩子们从有动力与他们交流的看护者那里学习。父母如何根据孩子的个人语言知识调整他们的演讲？为了回答这个问题，我们询问了亲子对（N= 41) 玩一个参考游戏，其中父母的目标是引导他们的孩子从一组三只动物中选择一个目标动物。父母在词汇层面根据孩子的知识微调他们的参考表达，为他们认为孩子不知道的动物提供更多信息参考。此外，父母在游戏过程中了解了孩子的知识，并相应地调整了他们的推荐表达方式。因此，以儿童为导向的语言可能支持儿童的学习，不是因为它被统一简化，而是因为它适合个别儿童的语言发展。