"migrant background" in German political discourse is mostly defined as "at least one parent was not born with German citizenship". That is incredibly broad and

"migrant background" in German political discourse is mostly defined as "at least one parent was not born with German citizenship". That is incredibly broad and covers both children of Syrian refugees who arrived last year, as well as children of a English-German couple or the children of a third-generation Turkish immigrant who has retained his Turkish citizenship but has lived in Germany his whole life. For the sake of this debate (how many children have adequate knowledge of the German language) it is essentially meaningless.