A normal baby should be able to turn over at 7 or 8 months of age. In general, the developmental process of babies is to lift their heads, newborns can lift their heads for 1-2 seconds in prone position, more steadily at 3 months, and very steadily at 4 months. For sitting, at 6 months, they can hold their hands forward and sit alone. at 8 months, they can sit steadily. at 7 months, they can consciously turn over from supine to prone position, and then turn over from prone to supine position. at 8-9 months, they can crawl forward, and it is best to start training at 3-4 months of age. Generally, at 11 months, they can stand alone for a few moments, at 15 months, they can walk more steadily, at 24 months, they can jump bipedally, and at 30 months, they can jump alone. For fine motor skills, children can generally move their fingers after the grip reflex disappears at 3-4 months of age, change hands or explore by pinching and tapping at 6-7 months of age, pick up things with their thumbs and index fingers at 9-10 months of age, and like to tear pieces of paper for play. At the age of 2 years, they can stack 6-7 square blocks, etc.