The word 'for'

In Russian there are 8 rules to learn about using the English word "for". I'm not exaggerating. I spent about an hour getting myself prepped and ready to DO my homework assignment. I think I did okay, but it sure was confusing. I'm glad to be learning this stuff though, because I know I sound a bit ignorant when I don't use the right words. It would be like saying, "I'm going to the store behind some ice". Instead of saying, "I'm going to the store for some ice". So I'm glad to finally be working through this little snafu!