The emergence of noun and verb categories in the acquisition of French

International audienceThis paper considers whether the child's early vocabulary shows signs of being organized into word categories. Two main kinds of evidence are looked for: i. differential production of fillers (referred to here more neutrally as Prefixed Additional Elements); ii. relevant phonomorphological variation for verb-words, and only in them. Results of analyses of natural speech production provided by the longitudinal studies of two French acquiring children followed between the ages of 1;3 and 2;3, show that there is a first period in which words seem to constitute one, formally undifferentiated, set. Differentiation between noun-words and verb-words appears progressively, as evidenced by the differential occurrence of PAEs in prenominal and in preverbal positions, and in the appearance of phonomorphologically relevant variations only in words that are verbs in the language. Looking at connected aspects of language, other phenomena are observed to occur at the same time, in particular, a significant increase in the production of multiword speech, that becomes the dominant way of expressio