If you've tried learning a romance language, you hate the subjunctive mood.
Sorry.
The subjunctive mood communicates wishes, hopes, requirements, or statements that express an unreality. We have subjunctive statements in modern English; they're just not inflected, so those verbs look exactly the same as non-subjunctive verbs. The only typical subjunctive phrase left standing after all this time is were, which is the subjunctive mood of the verb to be.
Along with the phrase I were—as in If I were a billionaire, I would own my own zeppelin—you'll also see the subjunctive used in clauses beginning with that and expressing something desired, recommended, or necessary.
They often follow verbs such as insist or demand, adjectives such as necessary or desirable, and nouns such as recommendation or essential.
Check out these examples.