For a simple example. I can still easily recall 1 to 10 in Spanish. This, I learned when I was 14. I use greek a lot as a second language now but I still hugely struggle with recall for 1 to 10 in Greek. In Spanish, which I haven’t used in over 2 decades I can hit it without pause to recall as fast as I can physically speak it.
What changes and can “tricks” be used to help recover the learning skills?