Ever been on a date where you get the feeling you're invisible? It's the feeling you get watching your partner check out every man or woman walking by. It could have been subtle, but you may have noticed anyway.

If the lack of interest is obvious, leave. Why invest time and effort in something that isn't going to pan out?

Our everyday interactions are filled with non-verbal signs -- also known as body language. And, in the world of dating, understanding this communication can be a huge asset.

Alan D'Souza, a 22-year old psychology major from Pune, relies heavily on these 'vibes'. "If she leans in while having a conversation, you know you're doing something right," he says. "I tend to look at my date and what she does with her hands. This is because the part of the brain that controls the motor skills of your hands is right next to the portion that controls your speech."

To help those who do not have Alan's insights, here's what you should watch out for.

Reading the senses

They say your eyes are windows to your soul. Sounds like a clich�, but it may be true, at least on a date. You can look into your date's eyes and read if they show interest in you, or if they betray a sign that your date is praying for a natural calamity to get out of the situation.

Gaurish Korgaonkar, a 25-year old marketing executive based in Mumbai, relies on eye contact. "Of course, someone who is shy will need a little prodding and take time to relax. Once relaxed, however, constant eye contact is vital."

Restless eyes are not promising -- the kind that constantly scan surroundings and fail to settle on you. On the other hand, a touch on the arm is a big leap forward -- a sign that your date is comfortable with you. Alan believes that any kind of touch communicates interest. She could be running her hands through her hair, for instance, in a way that says she wants to look appealing and make a good impression.

Jaya Bodke, a 28-year old who works at a bank in Mumbai, finds this behaviour common in men as well as women. Men like to draw attention by adjusting their clothing, thus drawing attention to their bodies.

A smile can say a lot

Next to eye contact, a smile is the most important non-verbal sign we send out or receive on a date. It is our reaction to any pleasurable stimuli and is a no-brainer. A blank face or forced smile in response to your jokes is discouraging. It can make you feel like a performer whose act has fallen flat and is now afraid to step under the spotlight.

Silence isn't always golden

Pregnant pauses could have two meanings. They are good if combined with a lot of eye contact and smiles. They are bad if your date is constantly fidgeting or keen on finishing dinner and making a run for it.

If your attempts at conversation are met with monosyllables, you could be headed for disaster. Jaya believes interest can be judged by participation. A lazy response could mean your personalities don't match. A lively conversation usually involves a lot of emphasising through gestures and facial expressions.

In a tearing hurry?

Compared to the other signs, this is more subtle. According to Shubham Saraf, 26, who works in Mumbai's hospitality industry, a date's reluctance to leave is one of the most positive signs. Even taking your time to order means you want to prolong your time together. Making impromptu plans to extend your time is also encouraging.

Observe and learn

While these are some of the signs commonly sent out and interpreted, there are many others that come into play, depending on the situation and persons involved. Moreover, while on a first date, it is unlikely that the two of you will hit it off instantly. You need to give it some time and not let a sign or two discourage you.

Alan recollects a date where things were headed downhill. "It was clear we had nothing in common; she kept staring at everything but me," he says. "That is until we began talking about our friends. We soon realised that, although we had no common hobbies, we had similar personalities. As the evening progressed, she started looking me in the eye, smiling, leaning in and using her hands to gesture."

A little effort and things certainly clicked for them -- she called Alan the next day!

While all these signs are insightful and offer an excellent advantage, exercise caution when drawing your conclusions. Arms crossed over one's chest could be an attempt to warm oneself, rather than a gesture of defensiveness or discomfort.

All theories on non-verbal communication clearly advise against using just one sign to judge. Remember to take into account the external environment and other influential factors. However, don't forget to relax and enjoy your time together. The rest will take care of itself.

Can you read dating body language? Share your experiences