Here, at this early age, the babies start picking the language tounges and the pattern of language. One of the most important milestones is listening, when babies begin to respond to sounds and react in various ways to different voices, e.g. by turning their head or even getting excited. Coo and gurgle: the rudimentary sounds that feature the process of speaking at this age are coos and gurgles. In view of the Cognitive Development Theory given by Piaget, such early vocalization is related to sensorimotor stage where the infant starts trying to learn to explore his/her surroundings using the senses (Piaget, 1962). The Social Constructivism developed by Vygotsky also emphasizes that through social interactions (including parents speaking), a baby is directed towards language acquisition through language skills scaffolding (Vygotsky, 1978).

Babies will learn at this stage to tell apart sounds and words. The milestones related to listening involve an ability to respond to familiar sounds and voices, and the milestones related to speaking would be the ability to babble, imitate speech sounds, and play with vocalizations, which would seem similar to how adult speech is pronounced and tones. This is the initiation level of pre-linguistic development when the infants build blocks of speech. Vygotsky emphasized that the language acquisition depends significantly on the verbal exchanges that the babies share with the caregivers since they apply the early sounds to social communication. This fact is also in line with the theory of Piaget since the babies are not yet in the symbolic stage but still in the sensorimotor stage of communication though gestures and sounds are used to express their needs and emotions.

At this point, infants begin to recognize simple words in language like the commands, such as, come here or give me the toy. The first words about one or two are marked as the first stages of vocabulary development. At this age, babies start relating definite words with action or objects and this introduces the basis of more complicated communication. Language development during this age group is in line with the preoperational level described by Piaget but which involves the ability of thinking symbolically and therefore children can use words as symbols of a thing or of an idea.

Children start treating words into simple phrases like want cookie or go outside. Their listening also increases and they are able to be understood by simple commands such as, sit down, or take up the toy. It is at this point that toddlers start developing initial sentences and this is a big milestone towards advancing their language. This is according to Social Constructivism by Vygotsky because social interaction is even more important in determining their language skills.

Children are able to comprehend stories, inquire questions and take several steps at this age. Their vocabulary still gets expanded and they start constructing more complicated sentences. At this point, it is time when children begin having more advanced conversations, and their understanding of grammar is developed, but it can still be developing. Piaget supports this development to the preoperational stage when children have the language as an instrument of problem solving and understanding the world around them.

At this age children are able to relate complex instructions, use more elaborate grammar and also are currently learning how to tell stories. Their vocabulary is more explicit and there is also a chance to explain what happened, what they feel and think in deeper details. Their use of tenses also begins to correct and they are in a position to talk with their contemporaries and other adults. Vygotsky believes that social interactions at this age can be used to fine tune these skills in language as the kid uses his ever growing vocabulary through communication with others and understanding the world.