Principle purpose of this lecture is to present on Past Modals. Past Modals are: Should Have, Could Have, Would Have. Should have, could have and would have are sometimes called “modals of lost opportunity” because they describe situations when we are imagining that the past was different. The general rule of Should and Would is: Should for recommendation / advice: “If you want to lose weight, you should eat healthy food.” Would for imagining results: “If I were rich, I would buy a boat.”