If your child is 4 years old and still can’t speak, it may be related to hearing impairment, congenital developmental abnormality, brain injury, etc. Hearing aids, surgical treatment and medication are often used to improve the symptoms. 1. Hearing impairment: If the child’s hearing is abnormal, he/she can not imitate adults’ speech and has no ability to express his/her language, thus he/she can’t speak, which can be treated by cochlear implants or hearing aids under the guidance of a doctor. 2. congenital developmental abnormalities: such as cleft palate, cleft lip or tongue tie developmental abnormalities, etc. These causes can also lead to the child’s inability to speak, and can be corrected through surgical intervention. 3. brain injury: can also cause the child’s speech system development delay, can be under the guidance of the doctor to use, ganglioside and other drugs for treatment, avoid self-medication. If your child is 4 years old and still can’t speak, it is recommended to actively seek medical attention and be evaluated and treated by a specialist.