In French, the grammatical features of the immediate constituents of words greatly contribute to their identification as nouns or verbs and to meaning attribution: nouns are usually preceded by determiners while verbs can be preceded by pronouns, auxiliaries or prepositions, or can appear "bear" in the imperative form. When do children start using grammatical information to attribute meaning to words? To answer this question a comprehension study was devised in which 90 French-speaking children (30 at age levels 2, 3 and 4 years; age range : 1;8 to 4;11) were confronted with 15 pairs of images, one representing an object and the other an action performed by a person. For each pair, children were asked to show where they saw "X", where X was an homophone word that could function either as a noun or as a verb, depending on whether it was preceded by the determinate article or by the subject pronoun. For example, /pus/ means thumb when preceded by "le" (le pouce) and push when preceded by "il" (il pousse). Children were asked either the noun or the verb version of the homophone. Noun and verb functions, order of items, and position of the requested item on the screen, were controlled. Results show that already 50% of 2 year olds can identify beyond chance level (at least 10 over 15 items) the image as a function of the word's linguistic environment, showing an early sensitivity to specific linguistic properties of the language and the use of grammatical information for meaning attribution. This proportion increases with age, reaching 77% among the 3 year olds, and 93% among the 4 years. No difference between items requesting nouns or verbs was found.