[2] Traditionally, the term is applied loosely to cases in which one might expect a subjunctive form in related languages, especially Old English and Latin.
Modern descriptive grammars limit the term to cases in which some grammatical marking can be observed, nevertheless coming to varying definitions.
In particular, The Cambridge Grammar of the English Language narrows the definition further so that the usage of were, as in "I wish she were here", traditionally known as the "past subjunctive", is instead called irrealis.
According to this narrow definition, the subjunctive is a grammatical construction recognizable by its use of the bare form of a verb in a finite clause that describes a non-actual scenario.
The subjunctive example unambiguously expresses a desire for a future situation, whereas the non-subjunctive (indicative) example is potentially ambiguous, either (i) expressing a desire to change the addressee's beliefs about the current situation, or (ii) as a "covert mandative", having the same meaning as the subjunctive mandative.
[27][28] So do modern descriptive grammars, while noting that the "past" is misleading as it does not correspond to tense, using the traditionalist term only to differentiate it from the "present subjunctive" discussed in this article.
[30] The English subjunctive is the subject of many common misconceptions, such as that it is a tense, that its use is decreasing when it is in fact increasing, and that it is necessary or sufficient for counterfactuality in conditionals.
Most purists who witter on about it couldn’t actually pass a test on distinguishing subjunctive from nonsubjunctive clauses to save their sorry asterisks.
But then they don’t have to: Merely mentioning the subjunctive approvingly and urging that it be taught is enough to establish one’s credentials as a better class of person.