One in every 10 to 15 children has trouble with language comprehension and or speech. 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. 3 other people cannot understand what the child is saying, is mostly using vowels, or omitting the beginning sounds in words. By age 8 all speech sounds should be mastered. The child's words are mixed up and not grammatically correct at age 5. Between ages 3 and 4 years stuttering is common.