Irrealis moods are a category of verbal moods that indicate that certain events have not happened, may never happen, or should or must or are indeed desired to happen, but for which there is no indication that they will ever happen. Irrealis moods are also known as counterfactual moods and include the conditional, the subjunctive, the optative, and the imperative—all best expressed in this book as the might-be and the might-have-been.