#1 He says so. Obvious enough, right? If he flat-out says that he's into you, that's really all you need to know.
#2 His friend says so. Has a guy ever come up to you in a bar and told you his friend over yonder thinks you're attractive? If so, that is a definite sign he's into you. Guys sometimes send their friends to do their dirty work.
#3 He smiles at you... a lot. A smile can tell you so much about how someone is feeling. If he's smiling at you from across the room, and even while the two of you are talking, he likes you.
#4 He compliments your appearance. A lot of guys will tell you that you're "hot" or "sexy," just because they want to get in your pants. But if a guy is complimenting your haircut, eyes, or even your clothing choice, they want more than just a night with you.
#5 He compliments your interests. It's one thing for a man to compliment your appearance, but if he says you have great taste in music, movies, or hobbies, he's really into you.
#6 He starts up the conversations. Guys who initiate the conversation are THE best! They're also the ones who actually want to talk to you—which means they're interested in you.
#7 He stands really close to you. Proximity is a huge indicator that a guy is interested in you. If they're interested, they want to be as close to you as they can possibly get without seeming too creepy.
#8 He's touchy-feely with you. A guy who likes you is going to find excuses to touch you. If the guy in question is touching your arm, putting his hand on your lower back, or making any other small moves to touch you, he wants you.
#9 He flirts with you. Flirting sometimes happens when two people just get on a roll, but it can also be a huge indicator of some more serious feelings. A guy who's interested in you will be keeping his flirt on all day/night long.
#10 He ignores other people when you're around. It's really easy to tell who's into you when you're in a group setting. If he sees you walk into the room and leaves anyone he's talking to, just to come find you, he really wants you.
#11 He pays close attention when you're talking. Especially in a group setting. Not everyone is listening to the person who's talking. But if he is locked in, eyes on you, and commenting on what you're saying, he's into you.
#12 He gets noticeably jealous when other guys are around you. If he suddenly appears every single time another guy is chatting you up, he's into you. By putting himself between you and this other male prospect, he's eliminating your ability to get to know him.
#13 He pays attention to your likes/dislikes. He knows if you like peanut butter with your chocolate, or if you despise a certain food. When he knows these things and can act accordingly, this is just proving that he likes you.
#14 He always looks sharp. Meaning he always is dressed amazing, is well-groomed, and smells delicious. A guy who has his eye on someone is going to try his best to look great for them.
#15 He's on his best behavior. When you're hanging out with him in a group with his friends and they're all making crude jokes, and you notice he's being quiet and just laughing along, he's into you. He doesn't want to do or say anything that might offend you—in any way.
#16 He laughs at all your jokes. Your jokes aren't all funny—especially if you're just not a funny person in general. But if he laughs at most of the things you say that aren't even all that funny, he is thinking about asking you out.
#17 He divulges intimate details about his life. No guy is going to tell his deepest darkest secrets to just anybody. When guys tell you personal information about themselves, it's because they like and trust you.
#18 Eye contact. Eye contact is a huge indicator that someone is interested in you. When they could be looking anywhere else—at their food, the people walking by, etc.—but they're locked onto you, it shows their true feelings.
#19 You catch him looking from a distance. If you turn your head and see him eyeing you from across the room, he's interested in you. Guys don't gawk for no reason.
#20 He raises his eyebrows when talking to you. It's a proven scientific fact that a person raises their eyebrows when they're interested in what you have to say. So watch his facial expression the next time you're talking to him.
#21 He sits with his legs wide open. This symptom of interest is far more scientific than the others. When a male likes you, his primal instincts tell him to show off his best "assets." And our human nature tells us that his crotch is apparently what us women want to see.
#22 He does the plan-making. If he's initiating when you'll see each other next, where you're going, and what you're doing, he likes you. No guy goes to all that trouble for no reason.
#23 He always seems cheery around you. He's going to be in a good mood around you if he has feelings for you. So if you find yourself telling him that he's "always happy," it's because he's into you.
#24 He teases you. Just like when you were 6 and getting pushed in the mud by that little boy, teasing STILL means that a guy likes you. No matter what age, teasing is always a sign he's into you.
#25 He surprises you with something you like. Your favorite coffee, candy, or even awesome concert tickets to that band that you mentioned you liked ONE TIME—this is a clear symptom of interest.
#26 He goes out of his way to get/do something for you. Men seem to be pretty selfish beings by nature. So, if he's going out of his way to do something special for you or buy you something nice, he definitely likes you.
#27 He tickles you. Tickling indicates that he wants to touch you, hear your laugh, and see that adorable smile you've got. All of which are huge signs he's into you.
#28 He calls you. With texting being the primary means of communication between two people nowadays, a guy who actually makes the effort to call you is the guy who likes you most.
#29 He asks about your day. Guys aren't really ones for small talk. But if he's asking you about how your day has been, he wants excuses to hear from you—and maybe he really does care!
#30 He asks personal questions. When a guy is just being polite, he'll ask surface questions, like "what's your job," "where are you from," etc. But if he's into you, he'll delve deeper into your personal information.