If you are 5 years old and do not speak clearly, you should consider short tongue ligament, uncoordinated mouth muscle function and mental retardation. 1. short tongue ligament: when the tongue ligament is too short, it will restrict the normal activities of the tongue, and the tongue cannot extend outside the mouth or touch the upper lip upward, resulting in unclear speech and incorrect pronunciation of upturned sounds, such as he and milk. Timely consultation is needed to be treated with tongue ligature orthopedic surgery. 2. Uncoordinated function of mouth muscles: the strength and control of muscles such as lips, tongue and jaw bone are not well developed, resulting in unclear pronunciation of corresponding labial and glottal sounds. It is recommended to go to the pediatric rehabilitation department for speech test evaluation, and under the guidance of the doctor to blow balloons, tongue wrapping, lip smacking and other corresponding mouth muscle and lip muscle training; 3, mental retardation: 5-year-old babies, in addition to unclear speech, also have slow movements, unable to use language to express correctly, need to timely consultation, improve the head MRI and intelligence assessment and other tests, through early intervention and rehabilitation training to enhance the language ability of the child. 5 years old This is a good time for language development. Parents can take their children outdoors more often and expose them to different types of people to broaden their horizons and exercise their expressive skills.