- For children you use -kun for a boy and -chan for a girl.
- For cute girls you might use -chan to emphasize her cuteness even though she is grown up. (Don't use this in the wrong setting, like the workplace.)
- For a man of lesser status you might say -kun even though they are adult. (Yeah, that's a putdown.)
- For someone of similar status or somewhat respected you use -san
- For someone much greater than yourself you would use -sama
There are many more, but those are the most important ones. There are also cases where they can take on slightly different meanings based on context. Here are a few common ones relating to the status of the person you are addressing:
- -senpai: Your senior in school or work.
- -sensei: A teacher.
- -nisan: Your older brother.
- -neesan: Your older sister.