I am right hand dominant but have learned to do a number of things with my left. I believe my son is ambidextrous. Up until about the third grade, he wrote with his right hand because he was expected to. Between the 4th and 5th grades he would do a lot of writing with his right but when his hand got tired he switched to his left and now that he is in the 6th grade he does things the other way round-starting with his left hand and then switching to his right.