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.
Great teachers do it all. They have to. Across all ages, languages, ethnicities, and subjects, teachers are, and need to be, some of the most widely skilled people around in order to be successful. A day in the life of a teacher can vary greatly depending on the subject and grade level in which they teach.