Human beings distinguish themselves by speech. It is a free gift given by nature to them . It is biological also. Biological system involves nervous system of the body. Just as the child grows physically in body, structure, limbs in the same manner his brain cells grow and develops the mechanism to identify the forms with that of language. Piaget in his cognitive development theory says pre operational stage is the space to acquire language (mother tongue) i.e from 2-7 years. In Upanayana ceremony that is held at 7 years , say this period is best to start learning writing , reading and other academics or to send the child to gurukula. Bismillah ceremony is the one self for children of Muslims , performed at 4 years 4 months and 4 days. This way of acquiring a language by kids before going to school has been studied or clarified by various ancient philosophers , modern linguists. Plato said it is innate knowledge ( a Priori) , to Descartes, learning a language means finding similarities between your own language and the target language. Skinner said it is by imitation ; set of rules and many more things. For Noam Chomsky it is language acquisition device - krashen zone of proximity. The brain lifts the structure patterns ; sound pattern ; syntax ; grammatical elements as it is spoken by the people in ones environment, may be by father , mother etc, the same structure patterns ; sound patterns are recalled and used by child in known and unknown situations. This article speaks about issues related to language acquisition , theories claims , similarities and differences in their theoretical claims. Keywords: acquisition ; gurukula; cognitive development ; bismillah; upanayana; imitation etc.