Multi-language spell check is on the backlog.
An error occurred while saving the commentHugoJ commented
This is ironically the worst way to push for making this feature a reality. As of today (6-may-2020) this feature request only has 1027 Votes. And that is more than two years since it was suggested. Users who need spell checking in other languages quite probably don't even speak English well enough to find this forum, then to find this post, and then to Vote it up. If decisions are made primarily based on the popularity of an idea in this forum, then this feature will never come to fruition because there are millions of English only speakers who won't care if this ever happens or not.
It should just be taken for granted that spell checking in multiple languages is an essential feature for a software solution being promoted on the global market.