One is about a self-centered, on causalidade to the proper action, characterized for the absence of objective relations between the way (use of the corporal action) and the end to reach (toy moved away from the child). These behaviors show that the child in this age it is already capable to recognize objective relations of causalidade, in the measure where if it serves of ways appropriate to reach its ends. The slight knowledge of objecto permanent and causalidade are not abstractos concepts, data that if they point out the level of the share and not of the representation. They are before practical categories or projects of action. For return of the year and way, the child starts to think. For Piaget, the thought is closely on the motor projects to the concept of objectos and its characteristics. It also imitates events that it sees to uncurl it its return. In the end of the stadium sensrio-engine other cognitivas structures are developed, the child starts to distinguish I from everything the remaining portion encircles that it and acquires the time and space slight knowledge.
She is also in this period that the child starts to speak. The Daily pay Period of training – she draws out yourself approximately of the two years to the six and characterizes yourself for the fast development of the language and the symbolic function. When she plays, the child can for example, to use two parts of ' ' lego' ' to represent two people. is in this height that starts to classify to command the objectos as well as counting. The moment where the child substitutes the action for its representation, that is, where if it serves of symbols, marks the beginning of the thought. The use of the language still allows an exchange it of information with the others.