Babies usually start babbling and uttering words such as "mama" and "dada" as early as four to six months from birth. They learn rapidly, and begin to use inflection and meaningful words for communication by 13 to 18 months.
Between 19 and 24 months, babies can say about 50 words and are able to string words together to make primitive sentences. Soon after, they find the appropriate volume to use while talking and get the hang of pronouns such as "I," "me" and "you." By ages two and three, they become quite sophisticated at speech and should be able to sustain conversations.
Parents can help a child develop language skills by speaking to him regularly and using clear, structured language around him. Body language and responsiveness are also important. If the baby doesn't show the appropriate signs of verbal development, parents may want to discuss the possibility of a language delay or hearing problem with his doctor.