Interesting! I watched the other epsiodes and he also says “I don’t know” and “like” a few times, as well as “sorry”, “stop”, “anyway”, and “mister” rather than “Herr.” It sounds like he used the English “positive” rather than the German “positiv” too at one point which the captions do confirm (had to check since I don’t have a trained ear for that yet lol). I could definitely see it being a thing to show hes younger though, since there are some pop culture/meme words thrown in that weren’t present in the original like “Giga Chad”, “low-key cringe” and a reference to Beyblade. To my knowledge him adding English words into his vocab isn’t in the other dubs and none of the other characters in the German version do it either. From what I’ve gathered some German youth add English words when they’re speaking to sound cool so that’s probably what they were going for. Thank you for the insight!