The subjunctive is a grammatical mood used to express wishes, hypothetical situations, or actions that are not certain to occur. It often appears in sentences that convey desires, suggestions, or conditions contrary to fact. For example, in the sentence "I wish that he were here," the verb "were" indicates a situation that is not real. In English, the subjunctive mood is less common than in some other languages, like Spanish or French. It typically appears in specific phrases, such as "If I were you" or "It's essential that she be present." Understanding the subjunctive helps clarify the speaker's intent regarding possibility and reality.