Between five and six Milestones Has a sentence length of 5-6 words----5-6个单词的句子 Has a vocabulary of around 2000 words (2000单词量) Defines objects by their use (you eat with a fork) and can tell what objects are made of (定义物品的用途,例如"你用叉子东西", 并能识别物品是由什么做 ...