Transactions of the Philological Society vol:111 issue:3 pages:301-325
This article accounts for the transition of Old English IS ‘is’ and BIÐ ‘will be’ from separate verbs with an overlapping past tense WÆS into a single, non-overlapping suppletive paradigm in Middle English, in which IS became limited to the indicative singular and BIÐ to the indicative plural and all other forms. I first analyse the synchronic situation in Old English, showing that IS was mainly used for predicating present states of specific subjects, and in identifying clauses. By contrast, BIÐ was used to encode future situations and generic statements, which are connected to future situations through their implication of future validity (compare expressions like boys will be boys). Importantly, the high frequency of generic statements, which are about kinds instead of individuals, also led to plural forms of BIÐ being more salient than those of IS. Second, I show how environmental constructional change can account for their merger. Specifically, the grammaticalization of the construction [shall Inf] brought about semantic erosion of the sense of futurity in BIÐ. The subsequent semantic confusion between BIÐ and IS led to a reanalysis of their distribution, which was guided by their number asymmetry: BIÐ was restricted to plural and IS to singular number.