Subjunctive Mood - English Plus
https://englishplus.com/grammar/00000031.htmA verb is in the subjunctive mood when it expresses a condition which is doubtful or not factual. It is most often found in a clause beginning with the word if. It is also found in clauses following a verb that expresses a doubt, a wish, regret, request, demand, or proposal. These are verbs typically followed by clauses that take the subjunctive: