This paper provides a new analysis of partitives in English, words that denote parts of nouns as in a pinch of salt, a dash of vinegar, a pat of butter, a stick of chalk, and so on. It seeks to substantiate two fundamental tenets of Cognitive Grammar with respect to such words. One tenet is that the meaning of a linguistic expression is best understood in terms of the domain to which it belongs. On the basis of this tenet, the paper argues that partitives form sets in which they highlight similarities in general but differences in specifics. A partitive has not only a syntactic function but also semantic content which conditions its presence in a phrase. The other tenet is that the use of a linguistic expression is governed by the particular construal imposed on its content. On the basis of this tenet, the paper argues that the use of a partitive stems from the particular construal the speaker chooses to describe a situation. The occurrence of two or more partitives before a noun brings about semantic contrast, in which each partitive represents a different construal.