La légèreté en français comme déficience de mobilité

We propose a new type of syntactic deficiency that we call “lightness”, which is relevant for all major syntactic categories. It applies to both words and phrases. Lightness is taken into account by different aspects of syntax (word order, extraction, adjunction sites, subcategorisation). Light forms differ from both incorporated and traditional “weak” forms, in the sense that they can be modified or coordinated. We show that lightness is relevant for French word order in the verbal domain. Light forms must be closer to the head (the verb) than other forms.