Subjunctives are verb forms used to express hypothetical, unreal, or uncertain situations. They often appear after certain words like "wish," "if," "recommend," or "suggest." For example, "I wish he were here" (not "was"). To form the subjunctive, use the base form of the verb for all persons ("I be," "you be," "he be," etc.). It's important for expressing wishes, desires, or unreal situations.