The reasons why children do not speak include hearing impairment, language dysfunction and personality factors, etc. They can be recognized by their response to external sounds and their ability to produce sounds. 1. Hearing impairment: If the patient does not respond to the sounds around him or her, and cannot hear the environmental sounds or speech sounds, he or she may have a hearing problem, which may lead to the failure of the normal development of language function. 2. Language dysfunction: If the patient is responsive to others’ voices but cannot produce sounds in response, there may be a language dysfunction. 3. Personality factors: If the patient responds to external sounds and can produce sounds by himself/herself, he/she may have an introverted personality and a dull family environment, leading to a lack of speech. If accompanied by a single interest, repetitive behavior, etc. need to consider whether there is a tendency of autism. Children do not speak may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.