Subject and object in Old English and Latin copular deontics
The history of deontic expressions in several languages reveals some naturalness in (a) constructions involving BE plus infinitive/gerundial, (b) thematic object initially surfacing in the nom, (c) reanalysis via case accommodation in neuters to a structure in which the thematic object surfaces in the acc, and (d) animates being first to adopt the change obligatorily. Neuters permitted two analyses of the theme argument: (i) nom subject; (ii) acc object. BE and non-neuters of most word-classes favor the nom subject analysis. In Latin, impersonals in <i>-um</i> favored an object analysis. In Latin and OE the possibility of analyzing the agentive dative as a quirky subject in the (OE) type <i>us is to ponder the word/what is us to ponder</i> shifted the cues in favor of an analysis of the theme as structural object, whence overt acc objects.