This stage usually passes quickly. Possible cause is Normal development. Action to take Many children don't master consonants until age 5. Possible cause is Lisp or other speech impediment. Action to take If the impediment is marked, ask your pediatrician to recommend a speech therapist for an evaluation.
Possible cause is Stammering or stuttering.
Action to take Consult your pediatrician who may recommend an evaluation by a speech therapist. Action to take Consult your pediatrician who will examine the child and provide a referral to a neurologist, if necessary. Possible cause is Communication disorder or autism. Action to take Consult your pediatrician who will evaluate the child and recommend referral to appropriate specialists. Possible cause is Developmental problem with many possible causes.