This document provides a lesson on expressing conditional sentences using "if" and different verb tenses in English. It introduces the structures "if + simple past + would" and "if it/she/he were". Examples are given of sentences using these structures, such as "If I had more time, I would go to the tea party with you" and "If Mary were at home, she would sleep". The lesson explains that in conditional sentences with "if" and the past tense of "to be", "were" is used instead of "was" for all subjects (I, he, she, it). Some exercises are provided for students to practice forming conditional sentences using these structures.