Children’s late speech may be a normal physiological phenomenon with individual differences, or it may be related to genetic factors, environmental factors, autism and other disease factors. 1. Physiological phenomenon: If a child’s hearing, intelligence, behavior and comprehension are all normal, and he/she only speaks late, it may be related to his/her own developmental characteristics and is a normal phenomenon. 2. Genetic factors: Some children can be genetically predisposed to late speech, which is also normal and does not require special treatment. 3. Disease factors: If the child suffers from autism, mental retardation, hearing impairment and other diseases, it can cause late speech. If a child’s delayed speech is accompanied by other abnormalities, he or she should consult a doctor to identify the cause and provide targeted treatment.