In this article, we propose a contrastive, panchronic method of semantic-pragmatic analysis, which we find particularly useful for uncovering the subtle distinctions of meaning and use that are characteristic of particle(-like expression)s in many languages. By way of illustration, we offer an in-depth analysis of the synchronic uses and diachronic development of two cognate particles from two Romance languages, namely French déjà and Italian già, equivalent in some of their most salient uses to English already. Synchronically, we have identified fifteen different uses of déjà and già, of which eight are shared between the two particles. We argue that both the gradual diachronic expansion of the range of uses of both items, and the small, but nevertheless clear, differences of use among the two that we observe in synchrony, support an analysis in terms of polysemy, as opposed to monosemy. What we propose is in the first instance a synchronic description of the two particles. The diachronic facts adduced are principally used to support our contention that déjà and già are polysemous, and as an additional tool for identifying which uses should be regarded as separate senses.