How to know if a girl is interested

Probably one of the more confusing things for men about how women show interest is when women appear to be sending “mixed messages” – when they do something that makes it seem they’re interested, then do something that makes it seem like they’re being challenging or aloof. It’s important to understand why this happens.
Remember that for women, saving face is extremely important, no matter where in the world you are. A woman’s social reputation is tied to her desirability to men and her choosiness; there is little more damaging to a woman’s reputation than for her to be seen throwing herself at a man who won’t take her. Because of this, women’s efforts to show men they’re interested are often couched within efforts to seem aloof or disinterested.

This is probably the most common way you will see women expressing interest in you; they’ll give you a hint, then stuff it under sarcasm or aloofness.
There is a secret to understanding these scrambled messages women send though – it’s like a secret decoder ring for woman-speak. Here it is:

If a woman implies she is interested in you, you should accept the statement as a sign of interest and ignore sarcasm, aloofness, or feigned distraction as simply her efforts to protect her reputation in the event you do not feel the same or do not take action to lead her to a satisfactory conclusion.

In other words, it’s her insurance policy. By not throwing all her chips in by being completely overt about her interest, she allows herself some wiggle room to later say, “Oh, I wasn’t really interested in him, I was just kidding,” if things don’t work out.
Which means, of course, that your ears should perk up the instant you hear something that implies a girl is interested in you – then, pick up the pace and start moving things forward as quickly as possible (but, needless to say, wait a moment before springing to action – you must always have your actions seem your own, as opposed to being reactions to something the girl has done. Even a small pause of three or four seconds can sometimes be enough – just give yourself a little time and be very casual, nonchalant, and natural about things.

A few examples of things a girl might do that should serve as a strong signal to you she’s interested:

• She says you’d make a great couple, you look good together, anything like that
• She says you’re handsome or sexy
• She asks you where you live, especially if it comes at an unusual time in the conversation or out of the middle of nowhere
• She asks if you live alone or with friends or roommates, and especially if she asks if they are home right now
• She focuses more of her attention on you, especially if you’ve been quiet or other people are competing for her attention, but she’s still devoting a lot of attention to you
• She does something physically suggestive, like taking your arm and putting it around her or taking your hand and putting it on her, or putting her hand or legs on you
• She buys you food or buys you a drink

And, a few examples of things a girl might do immediately following one of these signals that you ought to just ignore outright:

• Turn and start talking to her friends
• Crack a joke or make a lame cover up (e.g., “You’re so handsome. Ah, I think I just say that to every guy I meet!”)
• Act distracted or aloof; start looking around, break eye contact, etc.
• Get quiet
• Get uncomfortable (e.g., “Well, I should probably go” – most likely if she was hoping you were going to do something, then felt jilted that you didn’t – when this happens, stop her and save her night!)

If a girl shows interest in you, then does something like one of the above, ignore it and proceed with her anyway. For instance, she says, “You’re so handsome. Or maybe I’m just drunk.”
You say, “Nah, I’d be handsome even if you were sober. Come on, let’s go grab a seat.”