How old can a child learn soft pen calligraphy?

Chess: 7-9 years old: 3-4 years old, painting: 4-6 years old, skating, violin, dancing; Seven; Fourth, calligraphy; Five: 5-6 years old, piano: 3-5 years old; Second; Sixth, the best age to cultivate children's specialties. First, abacus: 5-7 years old; Third; Eight: 2-4 years old: 4-5 years old