A 3 year old baby who can’t speak may have a poor language environment, hearing impairment, autism and other reasons. 1. Poor language environment: Parents usually have less language communication with their babies, and there are many different languages at home, such as Mandarin, dialect, Cantonese, etc. These poor language environments will affect the child’s language development, and he or she may not be able to speak at the age of 3. 2. Hearing impairment: In babies with hearing impairment, there is nothing wrong with the central or peripheral part of the language system. Rather, it is the hearing impairment that makes them lose the ability to learn by imitation and the ability to hear and recognize language, resulting in babies at the age of 3 not being able to speak. 3. autism: autistic babies have social disorders, lack of secure attachment to parents and relatives, language disorders or language development lags behind or even regression, babies 3 years old may also not speak. 3-year-old baby will not speak is not normal performance, the specific reasons to go to the hospital through the examination to determine.