Irrealis mood is a grammatical category expressing events that are not actual—such as wishes, possibilities, or hypotheticals (subjunctive, conditional); in poetry, irrealis constructions (“If I were,” “Would that…”) create spaces of longing, speculation, or alternate reality, allowing poets to explore desire, regret, or potentiality beyond the confines of the factual, as in Keats’s “O for a beaker full of the warm South!”

A grammatical mood expressing hypothetical, wished-for, or contrary-to-fact situations. Includes subjunctive and conditional forms. In poetry, creates alternative realities. Compare with indicative (factual) mood. Important for tone.