As children developlanguage the way they  communicate with  others changes. Children will often simplify their speech to accomodate the language learning of other children.This phenonmenon can occur at about 3 years of age ( Siegler,& Alibali,2005). 

Children can also  communicate using words that are  not heard.Deaf children often communicate using sign language.

Sign language is used by different people worldwide and it changes from culture to culture.The form we are most familliar with is American Sign Language (ASL).

ASL is comprised of many  different words and lots of complex grammar ( Siegler,&Alibali,2005).Both deaf and hearing  children develop grammar at simmilar ages, and both babble at simmilar ages ( Siegler,& Alibali,2005).

When first learning signs children can most accurately produce the location of a sign, followed by its movement .Children are often least accurate at producing the hand shape for letters or words( Bonivillian,&Siedlecki,as cited in Siegler,&Alibali,2005).