Surrey Database of Short Term Morphosyntactic Change: Case assignment on predicate nouns

The notion of 'short term morphosyntactic change' can be used to characterise changes
in the use of forms in a short period of time even when the forms themselves have
changed relatively little. The Short Term Morphosyntactic Change (STMC) Databases
explore change in six different morphosyntactic phenomena in Russian over a 200 year
period from 1801-2000.

Nouns in predicate position with the copular byt´ (‘to be’) may take either the
nominative or the instrumental case. The nominative is the case originally used
in the predicate. The instrumental is the innovation, which has expanded dramatically
over the last two centuries. The accepted view is that predicate nouns with more
specified temporal, referential or evidential properties favour the instrumental
(Nichols 1981, Timberlake 2004). These properties may be linked to the semantics of
the predicate noun (animacy, concreteness) and aspects of clause structure (such as
the tense/mood of the copula, word order, and the presence of dependents on the
predicate, for example adjuncts restricting the predicated property temporarily). The
statistics derived from the corpus show that while this view is correct with regard
to 19th century and early 20th century Russian, in the second half of the 20th
century the instrumental with predicate nouns became dominant and exceeded the bounds
of the constraints given (Krasovitsky, Long, Baerman, Brown and Corbett 2008). During
that period the instrumental forced out the nominative irrespective of semantic
restrictions. This general change has left behind isolated pockets of specific
lexical items (e.g. nouns of nationality or semantically bleached nouns), which
retain nominative use.