1 From non-canonical to canonical agreement

According to a widespread view, adjectives developed out of nouns in Proto-Indo-European, as shown by the fact that the border between nouns and adjectives was fluid in all ancient Indo-European languages, in which it can be shown that many adjectives originated from nouns which, given their meaning, were often used as appositions to other nouns (Brugmann 1888: 420-426; see further Meillet, Vendryes 1924: 530; Kühner, Blass 1890: 547-551 among other). In my paper I discuss how a number of nouns, often functioning as modifiers of other nouns, can give rise to a new word class, that of adjectives, crucially characterized by agreement in all relevant categories. I argue that incipient agreement is non-canonical, while canonical agreement is the last step in a change that results in transcategorization. According to Corbett (2006), canonical agreement is best represented by gender agreement as instantiated in many IE languages, while agreement in case is considered non-canonical (2006). Remarkably, case instantiates the most prototypical type of inflection, while gender is inherent in nouns and gender shift may be indicated derivationally. Among categories of nouns, number occupies an in-between position: it is an inflectional category like case, but it also displays properties of derivation like gender, as it refers to inherent features of referents (Dressler 1989; Boi