Players who will fool easily are called as poker players. If these players convince you that they are having weak hand instead they have strong hand, so that they can win some extra calls and can make more dollars as usual. This is exactly right, when someone fools you at table then you will lose money then the person who fooled you will win the money because of strong hands and behaving like he is dealing with weak hands. Don't ever let this poker tell to happen in your case, be cautious all the time when you are playing this poker game. With this same kind of acts, those which are bought up to steal your money will win most of the games when these things are happening regularly.
If the players are playing with weak hand probably he might be playing strong hand, called as bluffing. Just think about the situation, when a player is having a weak hand, he will not tell that his position is bad? that would be really stupid thinking.