Have any of you found strategies to help divide time between the practice and upkeep of multiple languages? I’ve read in multiple places that most people focus on learning one or two at a time–that makes sense. But what about upkeep? Is it valuable to set aside a smaller amount of time to upkeep “old” languages? (That is, besides what occurs naturally.) And how much time do you think makes sense for that purpose?
I tend to spend about 30% of my time listening to or reading in languages other than the one I am focused on. It also depends on the availability of interesting content in different languages. Languages can lie dormant, and when I start up listening and reading again, they quickly revive.