Build Your Baby's First Vocabulary It is important to encourage children's vocabulary development so that they develop the language and literacy skills necessary to succeed in school. The adults in a child's life play a significant role in helping a child learn new words. A very young baby may only babble in response to hearing your voice as you read, but when you respond back by repeating or expanding on his or her sound or offering a word with that sound, this back-and-forth interaction helps with language development.