Infants can respond to human speech in the first days and weeks after birth as their primary communication skill is crying with different tones to represent hunger, pain and pleasure.

By between two to four months old , their vocal development takes the form of "cooing and gurgling", a way of communicating pleasure which usually occurs when they're alone

At between four and ten months, they move in to the "babbling stage, which involves more consonant and vowel "strings". This development in communication involves using single words at between twelve and 18 months old for everyday objects of people with this number increasing significantly between eighteen to twenty eight months of age which can form phrases of two more words