Okay, so you can tell he likes you. Maybe he looks at you a lot, or says, "Hi," all the time. Or maybe he's even come right out and said, "I like you" or asked you on a date. That's all great if you like him back, but what if you don't? Here are some suggestions for how to turn down a guy.
How to turn down a guy: Be honest
Coming right out and saying, "I like you as a friend," can prevent a lot of miscommunication and embarrassment. You might think it's easier for him if you lie and say you have a boyfriend, or give some other excuse. But eventually, he might find out and be even more hurt.
How to turn down a guy: Don't start ignoring him
Ignoring him won't make his crush go away and is no way of how to turn down a guy. If you're not really friends and there's no reason for you to talk to him, then you can be brief with him. Don't return his stares with smiles and don't start conversations with him. These things will only give him the wrong idea.
If you are friends and he tells you how he feels, you two need to have a talk. If you still want to be friends with him, make sure to tell him that, too. Put yourself in his shoes. If you liked him and he wasn't interested in you in "that" way, you'd want him to tell you that instead of ignoring you or acting like a jerk.
How to turn down a guy: Don't lead him on
Sure, you might be flattered that someone likes you, even if you don't like him back, but don't lead him on so that you feel better about yourself. This can only lead to bad feelings and is unfair to him.
How to turn down a guy: What to do if his actions make you feel uncomfortable/he's become obsessive
If you feel like he's starting to stalk you—that is, following you around or calling you a lot when you've made it clear that you're not interested—talk to your parents or to a school counselor about it. You shouldn't have to feel uncomfortable or unsafe because of someone else's feelings toward you. And you should not feel at all responsible or guilty if he's become obsessed. Talking to a counselor about how to turn a guy down can help you understand this and can also help you figure out what actions will stop him from bothering you.