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.
Teachers are the essential link to delivering a quality education to all children. To achieve the goal of universal education, the world needs more, better trained and better supported teachers. Teachers have the single biggest impact on children learning (John Hattie, Visible Learning).