Slowly as children grow older, the negative statements used by their parents start having a stronger impact on their emotional development. They feel unloved, unwanted, undeserved and unprotected. ... It affects their emotional, cognitive and social development. They grow up with feelings of 'not being perfect'.
The things you say are the things they are going to grow up saying. ... Your words have the ability to easily hurt your children, even if you don't realize it. Those words that you fling at them in frustration may be words that they remember for the rest of their lives.
Hope this helped :)