In linguistics, clusivity is a grammatical distinction between inclusive and exclusive first-person pronouns and verbal morphology, also called inclusive "we" and exclusive "we". Inclusive "we" specifically includes the addressee (that is, one of the words for "we" means "you and I"), while exclusive "we" specifically excludes the addressee (that is, another word for "we" means "he/she/they and I, but not you"), regardless of who else may be involved. While imagining that this sort of distinction could be made in other persons (particularly the second) is straightforward, in fact the existence of second-person clusivity (you vs. you and them) in natural languages is controversial and not well attested.
The first published description of the inclusive-exclusive distinction by a European linguist was in a description of languages of Peru in 1560 by Domingo de Santo Tomás in his Grammatica o arte de la lengua general de los indios de los Reynos del Perú, published in Valladolid, Spain.
First-person clusivity is a common feature among Dravidian, Kartvelian, Caucasic, Australian and Austronesian, and is also found in languages of eastern, southern, and southwestern Asia, Americas, and in some creole languages. Some African languages also make this distinction, such as the Fula language. No European language outside the Caucasus makes this distinction grammatically, but some constructions may be semantically inclusive or exclusive.
Clusivity paradigms may be summarized as a two-by-two grid: