“…Müller, 2004;Müller and Pillunat, in press), although there is a dominant language, Müller et al (2002) have shown that cross-linguistic influence may occur in balanced bilingual children. The influence appeared in relation to grammatical phenomena: phenomenon X of language A is affected at the same time as phenomenon Y is affected in language B (Müller et al, 2002). Furthermore, grammatical phenomenon Z may only be affected in language A, never in language B, i.e., influence may be uni-directional (Müller, 1998;Müller, Cantone, Kupisch and Schmitz, 2002;Schmitz, 2006a, b).…”