Deutsche Gebärdensprache
Haase is a polyglot; he speaks German, English, French, Italian, Spanish, Basque and Esperanto, as well as the Catalan and Occitan. He is also able to read Latin, Ancient Greek, Sanskrit, Gothic, Dutch, Romanian, Russian, Maltese, Swahili and Sāmoan, and to communicate using German Sign Language ("Deutsche Gebärdensprache", DGS).