If the delay is due to environmental and sensory integration disorders, attending early childhood education can be very helpful because the patient can build interactive and playful activities with peers and can also do sensory integration training, which can improve language function. If the delay is caused by autism spectrum disorder, mental retardation or hearing impairment, it is useless to go to early childhood education because it involves many professional medical treatments, such as physical therapy, acupuncture and oral muscle training for most autistic patients, cochlear implants or other professional treatments for hearing impairment, and mental retardation, which requires finding the causes of mental retardation, such as genetic metabolic diseases. In the case of mental retardation, we need to find out the causes of mental retardation, such as genetic and metabolic diseases.