Since old times the promptness of mastering speech skills characteristic of children, the stability of developed speech abilities and apparent, in any case enviable, easiness of treating complicated and delicate language phenomena has attracted the attention of not only specialists, teachers and linguists but also an immense number of people interested in learning foreign languages.
Insistent calls to develop «adult» methods of teaching foreign languages similar to or resembling the process of mastering speech habits by a child are still heard in our days.
In a number of cases, which cannot be all mentioned in this article but which are well known in the history of methods, such attempts were repeatedly made leaving rather noticeable signs in terminology: «a governess’ method», «a direct method», «deep absorption», etc.
Common for the most of these approaches was the desire to make the process of teaching, its dynamics similar to the conditions of language mastering under the circumstances approximate to the specific forms of a child’s speech activity.
The attempts of this kind exhibit an apparent pragmatical purpose — to achieve sound speech knowledge quickly, with the use of available observations and speech experience of a childhood period attractive by its simplicity and naturalness.
However, the simplicity itself, when based on its external distinctive features, turns out, as a rule, either unattainable, or accompanied by a great number of details the complexity of which makes one give up the attempts of their simulation.
A question arises the answer to which resembles to a certain degree the answer to the attempts of creating «perpetum mobile»: is this approach appropriate from the principal positions of the present-day state of the language science, the psychology of speech, the ontogenetic principles of the development of human consciousness in social and historical forms of its existence?
The last work of A.R. Luriya published after the author’s death «Language and consciousness»  which seems to answer this question contains the following: «…a word not only denotes things of the outer world, actions, signs, relations, but also analyses and summarises things of the outer world, i.e. serves the means of analysis of the information received by a man from the outer world… while a word meaning expressed by a child of an early age has an affective character, by the end of the pre-school and by the beginning of the school age a word meaning is based on specific impressions of particular visual experience, and further life periods are characterised by complicated systems of abstract connections and relations standing behind words, and a word starts to introduce a particular thing into a known category of hierarchical systems of meanings». The quoted idea indicates not only the change of a word meaning content along with the child development but also the way consciousness is formed, words being its little cells. This implies that consciousness of the outer world develops during the period of the ontogenetic development of a child: «in the course of ontogenesis the word meaning changes along with the system of psychological processes standing behind the word, and while at the early stages affect is hidden behind the word and at the following stages — visual memory impressions, at the last stage it is already based on complicated systems of verbal — logical relations».
We would like to emphasise the words: «… at the last stage». The time comes when childhood is over, certain development stages come to an end, the speech experience serves the basis for the formation of a functional system of human behaviour regulation which is first of all associated with the sense aspect of the utterance. This process was studied by P.Ya. Galperin , it is described in his investigations of the formation of mental actions. A.R. Luriya indicates that these statements are of particular importance for scientific psychology, which considers complicated processes not as a result of biological development but as a result of social forms of human activity. In the course of ontogenesis in complicated systems of interaction with the environment through human communications a transition from sensual-visual stage of cognition to a higher level of intellectual analysis and synthesis takes place.
During this period a person is formed. The child’s speech appears to be organically involved in all manifestations of his personality in communications with other people.
Various development stages of speech activity of children from nursery to school age are traced in current psychological and linguistic literature (A. Gvozdev, E.O. Arkin, K. Chukovsky, T.N. Ushakova, N.I. Zhinkin, V.V. Davydova, D.B. Elkonina, M.I. Lisina, and et al.).
The native language, directly involved in the formation of a person, acts not only as an acquired means of intercourse but as an instrument of regulating the person’s behaviour, self-affirmation, actualisation of his ego, as well.
The person’s ego cannot be fully realised under the conditions of human communications beyond the native language.
The possibility of participating in verbal intercourse, gradually developing from the babyhood up to the age of personality formation, is realised as a natural state, requiring no rational comprehension. It may be assumed that the process of personality formation, which is on the whole accomplished by the age of 4-5, includes processes associated with the increase and complication of semiotic relations between a child and the environment that are reflected in syntagmatic and paradigmatic speech structures. In this connection the accumulation of vocabulary inevitably followed by the development of these structures is rather significant.
N.I. Zhinkin , referring to the statistics of E.A. Arkin, presents the following data: : During the first year only 9 words are mastered: By the age of one-year-and-a-half the number of developed words increases to 39: By the end of the second year 300 words are already in work: The vocabulary of a four-year-old child contains 2000 words.
It may be supposed from some indirect data that this child’s wonderful ability to master easily the most complicated language system in the course of communications with adults and children (without which the person formation is naturally hampered) is the well-known fundamental fact of ontogenesis.
The so-called «Mowgli» phenomenon, i.e. the return of children into human society after their stay at the early age among animals, exhibits, as may be judged from investigated cases, the impossibility to teach them so that they could have a complete command of human speech if they returned being over 7-9 years old.
In this connection the desire to teach adults a foreign language just as they have mastered their native language seems hardly reasonable, if at all possible and achievable.
From the point of view of speech mastery the notion «childhood» itself proves to cover not one common period of development but several different periods with typical levels of qualitatively various phases of person formation.