Answer
You should be able to tell by what they say in the letters. The fact that they are writing you letters says they like you.
if he stares at you and tell to someone he likes me or tell me he likes me
If you are going through that then you are going through the same thing I am. Don't tell that person if you do or you might get into a fight. If you win she/he might tell your crush and everyone else! If you must tell someone tell your best friend but keep it a secret between her/him and you.
Blondies aren't any different than other people. If you can tell when someone else likes you then you can tell when the blondie likes you
you can tell by their face.
tell them to get over you and date someone else.
If u find a change in someone's behaviour
Tell him
they'll flirt with you
Ask them or failing that waterboarding
Ask her.
Then tell that person if she likes you or just leave as is
you tell someone who he likes and then you tell them that he was talkin about her