I tried coding in Italian with Claude and it sounds somewhat less professional than in English. Like it uses different language than what you would expect in the context. In the end I felt the result on the work per se was pretty much the same, just his comments sound strange. Thinking about it again, it's probably because Italian developers don't really speak pure Italian between themselves, we use a lot of English words or distorted Italianised English words when talking about software engineering because all the source material we refer to is written in English and for many things we don't even have translations. Then you talk with a LLM and it actually tries to use proper Italian, when human speakers gave up long ago. So it sounds like a humanities scholar talking about software engineering, not like a insider. It is quite entertaining. I wouldn't say it sucks with non English languages by the way, I even tried describing a bug in dialect and was amused that Claude code one-shotted the fix!