This study assesses the part played by semantics in the emergence of grammatical categories in child language. Based on basic, real-world properties, we analyze each of the first nouns and verbs used by three French-speaking children, and code them along six semantic dimensions – animacy, concreteness, determination , distance, motion and number. We use multiple correspondence analyses and hierarchical clustering to model the categories of child language that emerge based on the above semantic dimensions. We then compare them with adult noun and verb categories. Our results show that a gradual organization of meaning takes place during language development, with a degree of variation from one child to the other, especially in the early steps.