Why does a child suddenly start stuttering

It might be because there’s an error or delay in the message that a child’s brain sends to the muscles of her mouth when she needs to speak. This error or delay makes it hard for the child to coordinate her mouth muscles when she’s talking, which results in stuttering. Stuttering runs in families.

Anyone can stutter at any age. But it’s most common among children who are learning to form words into sentences. Boys are more likely than girls to stutter. Normal language dysfluency often starts between the ages of 18 and 24 months and tends to come and go up to the age of 5.