u/CharityUsedIodine

Subjunctive: If there were no subjunctive in English, you would have to write a sentence like this differently. The subjunctive indicates wishes, desires, commands, and anything contrary-to-fact or impossible. The English subjunctive tends to use these modal verbs: would, could, must, might, should.

The difficulty with the subjunctive in English is that it has almost completely collapsed into other constructions, especially the conditional. Almost. There are three main exceptions: 

1. Set phrases, like “Be that as it may,” “Suffice it to say,” and “Heaven forbid.”
2. Present subjunctive: Using the bare form of the verb—the infinitive without “to”—instead of the normal conjugation, especially in the third person, but also with “to be.” It is also present in other persons and numbers, though the form is identical.
   • He must take care to be on his best behavior.
   • I desire that she be present. Do you desire I be, as well? 
   • I suggest we resign ourselves to a short break.

    

3. Past subjunctive: When expressing the subjunctive in the past and using forms of the verb “to be,” the word “were” is used in place of “was.”
   • If I were there, I would give him piece of my mind.