Happily, for return of the 2 years the majority of the children already has a number of vocbulos that allows them to express itself verbally with easiness. Some in this age, and until a little before, already use simple phrases, with verbs, adjectives and prepositions, tell facts and create its proper vocbulos. However, beyond the individual differences, that must be respected, we need to be intent the determinative factors in the acquisition, and that when modified, can intervene with the normal development of the language. These factors can be subdivided in biological, psychological and social. Biological factors? Integrity of S.n.c. (Sistema Nervoso Central): children with neonatal anoxia must have its development of observed language more intently; Normal intellectual development: significant delay in the neuropsicomotor development together with delay in the acquisition of language, can be indicative of mental deficiency; Integrity of the auditory system: we stand out here the importance of the auditory selection to the birth for the precocious detention of the auditory deficiency; Integrity of the peripheral agencies of speaks (lips, language, palato, cheeks): beyond the nutricionais properties of maternal milk, to suck in the seio, propitiates the child the exercitao of the intra-verbal musculatura, preventing or minimizing orthodontic and articulatrios problems. Children with fictions lip-palatais can present alterations of language and articulatrios; Psychological factors. Affective bond between mother-child contributes effectively for an evolution of very satisfactory language; Social factors? Tense environments, of fight frequent between familiar, super protection (parents that do not give to the child learning chance, make everything for it), are poor models of language in such a way in amount how much in quality, and also can not only harm the language, but the global development of the child. As we can observe, discarding it possibility of injuries (factors biological), the parents and the environment have basic importance in adequate the global development, the learning and over all in the acquisition of infantile language.