From what age should you start punishing your child for wrong things he does?

Hi, I am not sure if you are trying to refer to disciplining your child or specifically punishing, but I would say a better way to go about it is to discipline. In fact, the earlier you start, the better. Instead of punishing your child, it is always better to instill a sense of right and wrong, and you can do it while your child is still a toddler, say about two years of age. So, each time your child does something that is not correct, rectify it and show your child what to do instead. Also, you can regularly use the words 'sorry' and 'thank you.' For instance, whenever your child does something correct, point it out, appreciate it and say thank you. If your child is shouting, say something like 'shouting is not good, you stop shouting and then we can play.' Also, the more you lead by example the more your child will learn :) All the best!