@marind I follow many non-English speakers on twitter, and translate function for their posts were useful, especially if I could get the general theme of the content from my limited reading ability.
Some users had two accounts, one english, one (e.g. Russian). Others posted in one language or another depending on the topic.

If language preferences of what you see in your local timeline can't be specified, it could make sense to have an account on an English dominant and French dominant account. E.g. I'm seeing a lot of foreign language post on my local thread which at the moment are not as useful as I don't know who they're from or if the context is worth me reading. I can scan through English, but other languages obviously take a little longer.

I suppose I would like to see *all* posts from people I follow, regardless of language, but probably limit languages that come through the local or federated timelines.