Early and child multilingualism: acquisition of German and the Romance languages by monolingual, bilingual and multilingual children.

The acquisition of German and the Romance languages as L2 and L3 by monolingual and multilingual (heritage) speakers.

Code-Switching, Code-Mixing in childhood and adulthood.

Syntactic variation, complexity and parametrisation.

Generative Grammar for German and the Romance languages.

Psycholinguistics.