Case marking and alignment

In (1) the syntactic functions of S (gizona ‘man’ in 1a) and O (mutila ‘boy’ in 1b) are identically coded, while in (2) it is S (muzhchina ‘man’ in 2a) and A (muzhchina in 2b) that are identically coded. That is, the two languages differ in whether S is aligned with A or O. Henceforth we refer to syntactic functions such as A, O, and S as argument roles. Argument structure has to do with the number of arguments and their roles; valence has to do with the morphosyntactic treatment of these roles, including their marking with particular cases. Alignment is the identical vs. distinct coding or treatment or behavior of argument roles that are different at some other level or in some other part of the grammar. Put differently, alignment is neutralization of valence-specific argument roles in particular morphological or syntactic contexts. Alignment, from our perspective, holds between sets (usually pairs, sometimes triads) of argument roles that