The most common first word said by a baby is a variation of "mama" or "dada." Other early words include "hi," "buba," "dog," "ball," "no," "cat," "nana" and "bye."
WebMD explains that some parents mistake babbling sounds for words. For instance, if a baby babbles a string of "da-da-da," it could be interpreted at "daddy" when the baby does not have any meaning behind her babbles. However, most babies do say simple words like those listed above around twelve months and can say up to ten words by 18 months. The best way to build a baby's vocabulary is to talk and explain what objects are. During changing time, for example, the parent points out a diaper and tells the baby, "This is a diaper." Reading to the infant is another excellent way to build a baby's word knowledge.