Duolingo. It’s fun. They purposely make it a game, with drills, bite-sized learning, images, challenges, streaks, and so on.
I’ve met my daily goal 208 days running, and sometimes I put in a few more hours to make it into the next – tougher – league.
It’s not complete immersion, far from it, but there is enough variety and enough spoken language for me to speak and listen, as well as read and write.
And the regular practice is linking up those neurons. I can hear something and the jumble of sounds turns itself into something I can understand without me having to touch it with my thinking.
A long way from fluent, but it’s steady progress fifteen or twenty minutes a day.