1. “If your brother or sister can do it, why can’t you?”

Comparison between siblings. This is definitely one of the things you should never tell your grandchildren. Comparison is never good, no matter the context. Be it at school or at the workplace, it is not the best way to encourage a person.

And when we are talking about children, it is even worse. When they are little, kids begin developing their self-esteem, and telling them that their sibling is so much better at math or any other activity will not help them to have good self-esteem.

Even more, a remark like this can totally destroy their self-esteem in the long run. This will make their lives much more difficult later, in adulthood.

So, keep in mind that there are better ways to manage this and to tell your grandkids that they should put more effort into something. Try to have a more gentle approach and also offer to help them succeed.