I have terrible subject test scores(in the 500's), how can I raise them?

With SAT II scores in the 500’s, schools are going to look at your GPA as inflated. You can’t just hope your SAT score will improve, you need to make a more realistic list. As it stands now, your chance of getting into any of those schools is virtually nil. Your speaking 5 languages will make for an interesting essay but won’t override test scores. Good luck.