An example of manipulation of a person would be when a man asks a young child to come see his van because it has lots of yummy candy in it and then he takes the child away. Another example of manipulation would be a young child manipulating LEGO bricks to build a tall tower.
Yet another example of manipulation would be emotional manipulation. In emotional manipulation a person uses his power with another to get what he wants, which is usually to be taken care of in some fashion. He manipulates through emotions and mental distortion. Manipulation is seen as negative because it unknowingly forces others to do the bidding of another person.