Analogy, automation and diagrammatic causation: The evolution of Tibeto-Burman *lak

One areal feature of East and Southeast Asian languages is the grammaticalization of an augmentative-diminutive pair from the nominals ‘mother’ and ‘child’, respectively (Matisoff 1992). Many Sino-Tibetan languages further grammaticalize noun-class affixes from these kinship nominals, adding a parallel ‘father’ analogy in the process. Some Tibeto-Burman (TB) languages further grammaticalize the resulting kinship trio into numeral classifiers and lexical and clausal nominalizers. This paper presents evidence from the Ngwi branch of Burmic demonstrating a novel, yet parallel, polygrammaticalization process involving ‘youth’ (from TB *lak) as an analogous lexical source. Data from 30 languages inform a gradient reconstruction of two integrated, parallel clines: a nominal suffix series, YOUTH > SPROUT > SLENDER > OBLONG > GENERIC, complemented by a numeral classifier series, YOUTH(S) > AFFINAL KIN > CONSANGUINEAL KIN > NARROW > GENERIC. Both paths underlie the emergence of a collectivizing clausal nominalizer. The results support an emerging consensus: Analogy, automation and diagrammatic causation are irreducibly interdependent components of grammaticalization.