-chan is a close friend or your child/grandchild/niece/nephew -senpai is someone older or higher class (a teacher or upperclassmen) (I'm 15 so most of you can call me that, if you want) -kōhai is someone younger than you (me @ most of you) -kun Women use it for men they've known for a long time, mostly to seem cutesy. -sama is used for a customer, or someone you GREATLY admire. don't use it very much, except sometimes for the person you're a -dere for (i dont know what to call that) -san is "mister" or "miss"