This paper studies the Cantonese sentence final particle tim1 and more generally the semantics of additive particles. The range of meanings conveyed by tim1 appears quite broad, covering both scalar and non-scalar additive readings as well as mirative ones. We argue in favor of separating an additive tim1-particle and a mirative one. Our claims are based on their semantic differences but also on syntactic and acoustic differences. We formalize the meaning of each of these particles using a probabilistic argumentative framework which helps us define the scale with which tim1 associates, namely an argumentative scale which is relative to speaker's goal in the discourse. In doing so we also contrast the meaning of each particle with similar elements in other languages. We use these descriptions to claim that the mirative reading is the result of a metonymic semantic shift of the additive reading of the particle, and discuss paths of semantic change for additive particles in natural language from a cross-linguistic perspective.Abstract This paper studies the Cantonese sentence final particle tim1 and more generally the semantics of additive particles. The range of meanings conveyed by tim1 appears quite broad, covering both scalar and non-scalar additive readings as well as mirative ones. We argue in favor of separating an additive tim1-particle and a mirative one. Our claims are based on their semantic differences but also on syntactic and acoustic differences. We formalize the meaning of each of these particles using a probabilistic argumentative framework which helps us define the scale with which tim1 associates, namely an argumentative scale which is relative to speaker's goal in the discourse. In doing so we also contrast the meaning of each particle with similar elements in other languages. We use these descriptions to claim that the mirative reading is the result of a metonymic semantic shift of the additive reading of the particle, and discuss paths of semantic change for additive particles in natural language from a cross-linguistic perspective.