A true necessary condition in a conditional statement makes the statement true (see  truth table  immediately below). In formal terms, a consequent N is a necessary condition for an antecedent S, in the conditional statement,  N if S ,  N is implied by S , or N S. In common words, we would also say . N is weaker than S  or  S cannot occur without N . For example, it is necessary to be Named, to be called Socrates. A true sufficient condition in a conditional statement ties the statement's truth to its consequent. In formal terms, an antecedent S is a sufficient condition for a consequent N, in the conditional statement, if S, then N ,  S implies N , or S N.
The Heart of Teaching: What It Means to Be a Great Teacher. What does it mean to be a great teacher? Of course credentials, knowledge, critical thinking, and all other faculties of intelligence are important. However, a great teacher should be much more than credentials, experience and intelligence.
One of my favorite attributes is perseverance, to truly be an outstanding teacher you have to persevere throughout the year. You have to be willing to show your students that you will not give up on them and to show them that if they keep on working and trying their best they can do anything.