A child’s greatest achievements are possible in play, achievements that tomorrow will become her basic level of real action.

In play, the child is always behaving beyond his age, above his usual everyday behaviour; in play he is, as it were, a head above himself. Play contains in a concentrated form, as in the focus of a magnifying glass, all developmental tendencies; it is as if the child tries to jump above his usual level.

The child begins to perceive the world not only through his [or her] eyes but also through his [or her] speech

What a child can do today with assistance, she will be able to do by herself tomorrow.

Every function in the child's cultural development appears twice: first, on the social level, and later, on the individual level; first, between people (interpsychological) and then inside the child (intrapsychological). This applies equally to voluntary attention, to logical memory, and to the formation of concepts. All the higher functions originate as actual relationships between individuals.

A child’s greatest achievements are possible in play, achievements that tomorrow will become her basic level of real action.

The true direction of the development of thinking is not from the individual to the social, but from the social to the individual.