The “SFB Register A10” project investigates why logical expressions can sometimes be expressed using one or more overt morphemes without changing the meaning. It explores whether this optional duplication is related to different speech registers—in particular, to how easily the central question in a conversation can be identified.

A10 is a subproject in area A "Register and grammar" of the DFG-funded Collaborative Research Center 1412 “Register”: Language Users’ Knowledge of Situational-Functional Variation.

In some cases, a logical expression can be signaled by one or more overt morphemes, apparently without a change in meaning.  This project investigates the hypothesis that optional morphological doubling is cross-linguistically correlated with a particular situational-functional property of discourse – namely, to what extent a unique Question Under Discussion is retrievable – and thus to register.