I'm Scottish, from the Isle of Lewis, and a native Gaelic speaker. I used to be conversational (B1) in German, but have forgotten almost all of it. I'd like to eventually relearn German and maybe hit B2 level. Happy to do English/German exchanges, delighted to do Gaelic/German exchanges. I can't help much with regards to English grammar (it's barely taught in British schools so you probably already know more about it than I do!) but I've spent many years in higher education (from Islamic History to Genetics) as well as working for employers such as the BBC, British Army, and University of Aberdeen. I can certainly help you practice more advanced vocabulary/topics/conversations if you want to practice professional or advanced English.