Late onset speech is a common problem in preschool. Most children start speaking by the time they enter kindergarten, however, about 7-8% of children have persistent speech disorders, cannot communicate with others in the same fluent speech as children of the same age, or always use the wrong words and do not have complete sentence structure. Some parents will be very concerned if there is something seriously wrong with their child, while some older people will say it is okay, instead delaying the best time to treat them. Many parents come to the clinic because their child is late in speaking, but it is also often overlooked or misdiagnosed. There are many causes of late speech: dysphonia or auditory hypoplasia, simple speech disorders, and intellectual disabilities that affect about 2-3% of children and are often accompanied by delayed language development. Autism spectrum disorders affect about 1% of the population, but receive a great deal of attention in the public and professional spheres. There are also normal developmental “variants” that are often misdiagnosed as symptoms of developmental disorders. I will briefly describe four conditions that are frequently encountered in child psychiatry: 1. Speech disorders: These are often persistent impairments in the acquisition and use of language (spoken, written, and signed), resulting from deficits in comprehension or language production: (1) reduced vocabulary; (2) limited sentence structure; and (3) impaired verbal conversation. Language skills are also significantly below age level, resulting in functional limitations in communication, social participation, academic achievement, and vocational performance. Approximately 50% of these children have emotional, social, or behavioral problems that improve with language skills. 2. Social Communication Disorders: Persistent difficulties in the social application of verbal and nonverbal communication. (1) communication for social purposes: greeting and sharing information; (2) the ability to change the content and form of communication according to the context and the person listening; (3) difficulty following the rules of conversation or storytelling: taking turns in conversation, changing wording when misunderstandings arise, and knowing how to use verbal and nonverbal signals to regulate interaction. 3. Intellectual Disabilities: Impairments that occur during development include deficits in intellectual and adaptive functioning in the conceptual, social, and practical domains. The following three criteria must be met: (1) intellectual deficits; (2) adaptive functioning deficits; (3) intellectual and adaptive functioning deficits that occur during development. 4. Autism: Persistent impairment of social communication and social interaction in multiple contexts: (All 3 symptoms must be present) (1) Social-emotional reciprocity. (2) Nonverbal communication behaviors. (3) Development, maintenance, and understanding of interpersonal relationships. There are also restricted, repetitive behaviors, interests, or activity patterns. In clinical practice the above disorders are often misdiagnosed, especially social communication disorder is often misdiagnosed as autism, and this diagnosis is clarified in the new US diagnostic criteria DSM-5. Because social communication disorders can be corrected scientifically, and these children have relatively good intelligence levels, they are more likely to be able to work in jobs that have little to do with words. Autism, on the other hand, is often unable to perform work in adulthood because of their impaired social reciprocity. Children with mental retardation are able to work at a level appropriate to their intelligence after instruction and learning of their language skills. Of course, it is also important to note that abnormal variations in normal development occur in children who are born extremely prematurely, have chronic illnesses, and live in difficult conditions. Generally, these children’s language skills develop by leaps and bounds between the ages of 5 and 6 years.