Children vary in their development of speech and language skills. Health professionals have milestones for what's normal. These milestones help determine if a child is on track or if he or she may need extra help. For example, a child usually has one or two words like "Hi," "dog," "Dada," or "Mama" by her first birthday.
Sometimes a delay may be caused by hearing loss, while other times it may be due to a speech or language disorder. Language disorders can mean that the child has trouble understanding what others say or difficulty sharing her thoughts. Children who have trouble producing speech sounds correctly or who hesitate or stutter when talking may have a speech disorder.
If your child's speech or language appears to be delayed, talk to your child's doctor.
NIH: National Institute on Deafness and Other Communication Disorders