>>4
>I'm thinking like ASL they'd be hard to retain since you'd hardly use them.
Do you mean American Sign Language? Out of all languages I have studied, I think I picked up ASL the fastest. While I was actively using it, it was one of the quickest/easiest languages I'd ever studied and I was able to communicate very well. I did "lose" most of it, but I think that's understandable after 6 years of 0 usage. However I'm fully confident that if I got around my deaf friends again, or took a class, I would re-learn it even more rapidly than the first time around. Maybe it's because I have a very visual memory?