This document provides information about a class on English grammar that discusses conditional clauses. It defines a conditional clause as a type of adverbial clause that expresses a condition, real or imagined. There are six main types of conditional sentences based on likelihood and tense: general rules, open future conditions, unlikely future conditions, impossible future conditions, impossible past conditions, and unknown past conditions. Examples are given for each type. The document concludes with an exercise involving 10 multiple choice questions about conditional clauses.