Case in adult L1 German

[Julia Berger-Morales]

Dear colleagues,

I am conducting research on the acquisition of nominal morphology in German
and am finding that children often substitute Accusative for Dative Case,
particularly 'den' for 'dem' in Dative contexts.  My intuition as a native
speaker of German is that this is a mistake that *adult* L1 speakers also
make, but I haven't been able to find any quantitative data on this matter
so far.  Does anyone know of any studies that address Case errors and/or
substitutions in adult L1 German?

Thanks in advance,

Julia Berger-Morales
Dept. of Linguistics, UCLA