Not GP, but in my case, I find my conversations with ChatGPT or Copilot often being in my native language. Whereas with Google, official docs, and StackExchage it's only and always English.

Obviously, the code I write in the end is English. But explaining a domain in a native language - especially when that domain embeds cultural things - helps a lot. For example, there's a massive difference between "add_high_VAT()" in a Dutch Context from a US context. Even add_VAT(lookup_VAT("FR", "low")) demands quite some domain-knowledge about EU tax system. Which I can express in English, but is much easier in my native language.