Subjunctive mood - Wikipedia
https://en.wikipedia.org/wiki/Subjunctive_moodThe subjunctive is a grammatical mood, a feature of the utterance that indicates the speaker's attitude towards it. Subjunctive forms of verbs are typically used to express various states of unreality such as: wish, emotion, possibility, judgment, opinion, obligation, or action that has not yet occurred; the precise situations in which they are used vary from language to language. The subjunctive is one of the irrealis moods, which refer to what is not necessarily real. It is often con…