How do you turn down someone

So we all have our right to be picky. How do you turn down someone who likes you. And even if you did turn them down they're still so persistent it's becoming annoying. Also what if that person is your friend(he got friendzoned) Ofcourse I don't want to end our friendship just because he was dumb enough to like me.

I say just be honest and tell him you don't like him that way since he went out an told you he liked ya he may as well already knew it could of lead to rejection so he should of prepared himself before saying something like that shouldn't be your fault at all also being persistent about it is.. very rude an weird he should know better. he's supposed to be a friend so I think he could atleast respect your answer. o~o; if he can't now that's not friendly

it's really annoying me how he would always drop hints that he still likes me even though i turned him down and pisses me off that he's using my "username since i was a child" on games TT_TT It's really awkward!!!! D: I never liked girls who lead guys on even if the guy said he likes the girl but obviously the girl will never ever get to like the guy because we're programmed that way. So I already did tell him that I will never ever like him straight up. XD ALSO HE ASSUMED THAT WHEN I GO BACK TO MY COUNTRY(where he lives) WE WILL GO ON A DATE WHICH WILL NEVER EVER HAPPEN I NEVER EVEN SAID WE WILL D:

knives http://stream1.gifsoup.com/view5/3289856/osaka-knife-o.gif are your best friends

You either be honest and say no or you just ignore them forever

Honestly if you've made it clear to him you have no interest in him and he persist then the best thing to do would be what donnie said which is drop him or just be rude as hell about it to get your point across even more.