Hearing problems, low intelligence, or lack of verbal stimulation at home may interfere with the development of speech. Children with older siblings or one child in a set of twins may not talk because others talk for them.
Early detection is critically important.
Early intervention may prevent the problem from interfering with learning in other areas. If by age 3, the child is mostly using vowels or omitting the beginning sounds in words, or other people cannot understand what the child is saying, see a speech therapist. By age 8 all speech sounds should be mastered. Between ages 3 and 4 years stuttering is common. Most children grow out of repeating sounds and hesitating between words.