How do the language systems in a multilingual speaker’s mind/brain interact? This is the overarching research question addressed by the EU-funded project INSPIRE. The project will employ the eye-tracking and mouse-tracking technique to investigate real-time sentence processing in German native speakers in Norway and non-native speakers of German whose native language is Norwegian. The results will be compared to those obtained from a group of German native speakers in Germany. Unlike German, Norwegian has no morphological case on full noun phrases, but mostly relies on word order for sentence interpretation, which renders this language combination particularly interesting. The findings will be relevant for all who have to deal with multilingualism, including language therapists and teachers.