She's burping around you, punching you in the shoulder and calling you "dude." Welcome to the friend zone. It probably looks familiar because you've been here before, but now it's time to think about how you got there in the first place.
Girls have a variety of reasons for putting you on the platonic sidelines, and it's not always as simple as a lack of attraction. Here are other possible factors for her choosing friendship over romance.
Because you're too familiar
If she says you remind her too much of an ex, that might be because the breakup is still fresh, or maybe everyone reminds her of him. If she says you remind her of her brother, well, you probably look like her brother. You can't blame a girl for being honest about that.
She's not sure what kind of guy you are yet
When they get friend zoned, many guys assume it's because they were too nice. Girls aren't nearly as turned off by kindness as many dudes assume. Putting you in your platonic place may not be a conscious test, but your reaction may tell her a lot; it's an effective way to separate the (genuinely) nice guys from the aggressive, entitled-acting jerks.
Because she's attracted to someone else
It's almost impossible to entertain the idea of a romantic relationship with a person if you're hung up on someone else. She might be putting you in the friend zone because, for now, that's the only place where there's room. Take it as a compliment that she's not using you to get over another guy, and wants to keep you around.
Because she's too busy right now
While all relationships take work, friendships are lower maintenance than relationship relationships. That may make friendship seem more attractive to a person with a lot on their plate, even if there's mutual romantic attraction. In which case, a friends with benefits scenario may be possible, but exercise caution or someone could get hurt.
To give you a chance to grow up first
Getting sent to the friend zone is sometimes like getting sent to your room as a kid — you're there for acting immature. She might not hold that against you, but also not want to nag you into becoming the mature man of her dreams. She probably just wants a friend more than a project. The older you get, the more you'll appreciate people who let you grow up at your own pace.
Because she knows your history too well ... or you know hers
If you're acquainted (or friends) with someone in her sexual history, or visa versa, promoting you from platonic status might be too weird to be worth it. Even if your exes are cool with it, you don't always want to read the book when you've already got the CliffsNotes.
Because it's not about you -- she's dealing with her own stuff
It's very possible that she's friend zoning you because she friend zones everyone. Relationships are hard, and recognizing you're not ready for one isn't a bad thing. It's actually a pretty rad quality to have in a friend because it reminds you to work on yourself first.
To get to know you better before deciding to be romantic
Many girls aren't comfortable dating guys whom they wouldn't otherwise be friends with. That's not a bad thing. That's not even the friend zone; it's their comfort zone. Chill out, be patient and get to know her too, but don't make any assumptions about where it's going.
Because she genuinely just wants to be friends
If you don't see signs that point to any of the above reasons, it's probably because she sees more friendship potential than anything ... and she's letting you know that she doesn't want to trade being friends for a relationship she can't picture working out. Her first step in being a good friend is not wasting your time ... your next step is to not take it personally.