In more detail, a recent ERP study on professional simultaneous interpreters (Proverbio et al., 2004) showed a surprisingly close relationship between the number of languages proficiently mastered by these professionals and the response speed to L1 or L2 words in a semantic decision-making task. In other words, the more languages they speak (and the more vocabulary they have), the slower the lexical processing, even in their native language…

Т.е. чем больше языков ты знаешь, тем медленнее обрабатываешь информацию. Я, получается, медленнее распознаю слова, чем мой клон, не знающий английского.

И еще одно — когда лучше детям учить второй язык:

Indeed, when a second language is learnt after the age of 5 years, the L2 phonology contains a slight accent in the native language, which may be almost imperceptible, but is still always present. The same occurs for exposure to regional dialects during the first years of socialization, whether in the family or at school: these leave an indelible mark on the phonological and prosodic aspects of speech. Indeed, it has been shown that long intensive teaching programs (5000 h) in first graders can give results similar to those achieved in shorter programs (1400 h) given to second graders (Genesee, 1988).

from Mado A., Roberta A., Alberto Z. The organization of multiple languages in polyglots : Interference or independence ? // Journal of Neurolinguistics. 2007. Т. 20. С. 25-49.