State of the art ; Speech perception (biling.) ; Sprachperzeption (biling.) ; Bilingual speech production/perception; Zweisprachige Sprachproduktion/Sprachperzeption; Language processing (biling.) ; Sprachverständnis (biling.) ; Speech production/speech perception (biling.) ; Transfer (languages in contact) ; Adstratum language; Adstratsprache; Interference ; Mixed language ; Transfer (second language acquisition) ; Transfer (Zweitspracherwerb) ; Cross-linguistic influence (second language acquisition) ; Interference (second language acquisition) ; Processability theory; Language comprehension (second language acquisition)