From my experience you always have this weird feeling of something not being right. Its never really a word they say or a move they make with their body, just a feeling. One golden tip I have learned on my travels, especially in the Balkan regions for example, children or women with children are 70% likely to be fake. They build a whole system off of guilt where you feel compelled to give money. Now not all of them are like that, and you would be a monster not to help out a child or mother in need, hence why I said up there that its always the feeling you get. The saddest thing is really that, often times, these people don't keep the money for themselves. Its a large insidious cabal/network where these people are often working for a fraction of what they get on a daily basis, its a sad life to live. But my general practice is to often get them what they ask for rather than money. If someone tells me they need money for food, I go with them to the nearest bakery,store, cake shop, whatever really and buy them what they want. But there are instances where the darkness comes out. I have had one man ask me for money for food, and when I told him to just tell me what he would like to eat he started yelling profanities and asking why I don't trust him and what do I care what he does with the money he gets. Its a strange world out there.
Have a wonderful day friends.
Arthur.