How can a different perspective of speech and my actions sometimes so drastically make a difference between success and failure.
Tact is a careful consideration of the feelings and values of another so as to create harmonious relationships with a reduced potential for conflict or offense. It is a virtue. It is the ability to induce change or communicate critical and sometimes hurtful information without offending through the use of consideration, compassion, kindness, and reason.
A tactful person can tell you something you don't want to hear and you will be thankful for the information when they are finished.