I was with my friend Alison at a pub after work when she nudged my shoulder. "Hey, look at that cute guy!" she whispered. "He's glanced my way several times now. Do you think he's interested in me?"

I turned a little to look. He'd turned back to the bar, had his back squarely to us, and had his arms crossed across his chest. "Sorry to disappoint you, Alison," I said. "Looks like that one isn't open for negotiation."

Most of us aren't even aware of all the body signals we send out every single day. While women have a much more developed "vocabulary" of body language, men tend to use the same nonverbal signals to show that they are interested.

1. Checking You Out

When a guy first sees you, he will scan you from top to bottom. He will do this most likely while you are not looking, and he may not even realise that he is doing it himself.

You can often catch a guy checking you out, because if he is interested in you and feels comfortable doing so, he may do it a second time. You are meant to notice this time, and his gaze may almost seem to stroke your body, lingering over the places he likes best.

2. Grooming Behaviors

If he sees a girl he likes, he is going to want to make sure that he looks his best. He may run a hand through his hair, check to see that his shirt is tucked in (or not), straighten his tie or jacket or glance down at his clothes to make sure that nothing is amiss. If he disappears into the restroom (to check his teeth? to comb his hair?), he may return feeling sufficiently groomed to start making a move on you.

3. Getting Your Attention

If he's attracted to you, he will try to attract your attention. The way that he will go about it will be unique to him. Some guys may simply move so that they are in your line of sight. Other guys may engage in some extraordinary behaviour so that your attention is directed towards them. Whatever the case, if he is interested, he will want to make you notice him, so that he can gauge whether or not you find him attractive in return. For example, if he is with a group of friends, he will stand slightly apart from them, as it will make him stand out visually and be more likely to attract your attention.

4. The Face

An instant and obvious indicator of his willingness to know you comes when you first make eye contact with him. When you first meet him, watch his face. Is it friendly, open, and inviting? Does his face break into a spontaneous smile? Watch for the very subtle signals of attraction: raised eyebrows, parted lips, or flared nostrils.

He may touch his face a lot while talking to you as well, and this is a sign of attraction. When we are interested in someone, our skin becomes more sensitive and more pleasurable to touch. He may rub his jaw, lay his chin on his hand, or stroke his forehead. Similarly, if he has a drink in his hand, he will take more sips, or if he has a cigarette in hand, will take more drags. The tactile senses have been aroused, and he will likely be completely unaware that he's doing it.

5. Body Position

Just like women, men like to show their body off to its best state. A guy may flex or tense his muscles to draw your attention to them. He may stand up more straight than normal or lean forward so that he is closer to you. He may put his hands on his hips, as doing so accentuates the size of his body and creates a V-shape. If his is sitting, he may perch on the edge of his seat and lean towards you. If his legs are crossed, he will point his resting foot towards you.