The contrastive study of three domains of sentence structure constitutes the subproject "Microvariation in the sentential architectures" (MICROARO). Assuming that linguistic variation is determined by the properties of the functional categories and, in particular, by the properties of the features that conform them, we will undertake the study of those formal objects from an informational and processing perspective in relation to: the structure of determiners, the architecture of left periphery and its relation to discourse (focues, theme), the order of arguments and modifiers (adverbs and adjectives), the selection of temporality, aspect and voice, as well as its influence in adjunct predications, passive sentence and attributive clauses. Finally, we aim at studying the relation between the syntax of the clause and the lexical syntax, and we will attempt to determine which kind of lexical elements tend to be more likely to grammaticalize in the history of the Romance languages.