Ok but.. imagine German Bastion. They were (assumably) made in Germany and were there for most their life, so it would make sense that they would be able to understand the language.
Torbjorn getting Bastion a new voice box so they can speak and getting suprised that they speak German. He then proceeds to install English files on them as well
Bastion finding out that Rein and Angela also speak German and getting excited bc look!! someone who speaks my native language!! and they eventually become buddies
Bastion yelling/cursing in German whenever they’re angry, frustrated or ranting/venting about something. Rein and Angela are the only ones who understand and the former is like ‘who let this large metal child swear’
it was rein
Rein telling Bastion about German culture and traditions because they never really got to see all of that and maybe taking them to a festival or two?? he’s bummed out that they can’t try the foods though