Some babies may utter their first words as early as 9 months of age. It’s important to note, however, that learning experts differ in how they assess whether a first word has been spoken. For example, some experts suggest that the first utterance of any word that sounds like a word used by adults, such as “dada” or “mama,” counts as a baby’s “first word”. Other experts contend that “first words” are limited to words that a baby uses to name something or someone in a consistent manner. Whether a baby says his first words at 9 months or 15 months, the exciting news is that what follows is nothing short of a vocabulary explosion. Until three years of age, many children add 1-2 words a day to their speaking vocabulary. Three- to five-year-olds can add 4-6 words a day, five- and six-year-olds often add 6-9 words per day, and from age six, children can add up to 20 words per day!