The subjunctive is an indispensable means of expression in French. Its use is much more prevalent in French than in English, where an infinitive is often used instead. The subjunctive is a mood used to express an action that is dependent on a subjective idea, opinion, or condition.
The subjunctive is used after verbs and impersonal expressions showing opinion, doubt, need, want, emotion, denial, disbelief, preference, desire, permission, prohibition; after a request or a command; after certain conjunctions; after superlative expressions; after certain indefinites; in relative clauses; and in third‐person commands.
The present subjunctive is used to express both present and future time, while the past or perfect subjunctive is used to express an action that has already taken place. Although the imperfect and pluperfect subjunctive do exist, they have disappeared from the spoken language and are used and seen only in very formal writing.