each child is different. I think it is fine for a little kid to start with one lesson per week. the kid can join more classes when the kid is 2 years old.
they are different. Nursery class is 5 days. Or, You can join more lessons per week. It is cheaper than nursery class. no more extra money, such as uniform, 什費, 等等. besides, nursery class has more school holidays than playgroup.