It's strange how when you're learning another language and you are only fluent in language, everything language-related seems to be categorized into two categories. For me, it's "English" and "not English." When I was first learning Setswana, I would always reach for Spanish words, which made some pretty comical situations at times. Now when I'm trying to brush back up on my Spanish, I find myself reaching for Setswana words. The difference this time is that my Spanish is good enough that I can read simple books (I had my folks send me Harry Potter in Spanish), but now I can't find the words if I want to speak it. I had to look up the word for "yesterday," well, yesterday.
I bet Stephen Pinker could tell me why that is.