It is easy to speak negatively when we do not like something about someone. We first react to them in our mind and so tend to get angry. Our words and behaviour would then naturally be negative and insulting too. This further widens the gap and breaks the relationship.
When someone does something undesired, I first need to try and understand his behaviour. Every person has a reason to behave the way he does. If I can’t understand at that time, I at least need to give it time. The more I react to the other person and his behaviour, the greater the distance that is created. So I need to begin the first step of positivity by recognizing some positivity in him.