Chapter I. General information about grammatical categories of verb in english grammar 6

2.3.5. The subjunctive mood

Probably the only thing linguists are unanimous about with regard to the subjunctive mood is that It represents an action as a 'non-fact', as something imaginary, desirable, problematic, contrary to reality. In all other respects opinions differ.
To account for this difference of opinion it is necessary to take into consideration at least two circumstances:
1. The system of the subjunctive mood in Modern English has been and still is in a state of development. There are many elements in it which are rapidly falling into disuse and there are new elements coming into use.
2. The authors describing the subjunctive mood often make no distinction between language and speech, system and usage. The opposition of the three moods as systems is mixed up with detailed descriptions of the various shades of meaning certain forms express in different environments.
The development of the modal verbs and that of the subjunctive mood – the lexical and morphological ways of expressing modality – have much in common.
The original 'present tense' forms of the modal verbs were ousted by the 'past tense' forms (may, can). New 'past tense' forms were created (could, might, must, ought). The new 'past tense' forms must and ought have again superseded their 'present tense' opposites and are now the only forms of these verbs.
The forms be, have, write, go, etc., which were originally forms of the 'present tense', 'subjunctive mood' grammemes, have suffered a similar process and are now scarcely used in colloquial English. They have become archaic and are found as survivals in poetry, high prose, official documents and certain set expressions like Long live…, suffice it to say…, etc. The former 'past tense subjunctive' has lost its 'past' meaning, and its forms are mostly used to denote an action not preceding the moment of speech.
The subjunctive mood is used to express a wish or possibility. This mood has a limited role in English compared to other languages such as French or Italian, but it's important to use it properly in formal writing.
The subjunctive form of a verb (apart from to be) is made from the 3^rd person present singular, without the -s (or -es) ending. With these verbs, the same forms are used whether or not the context is the present or the past.
The subjunctive of to be is simply be in most cases, but were is used in certain constructions with if and to express a wish (see below).
The subjunctive is typically found in rather formal English constructions with that and with verbs such as suggest, demand, insist, ask, recommend, etc.:
It was suggested that he wait till the next morning.
They demanded that the prime minister explain who authorized the action.
The ordinary, indicative forms of the verbs in these examples would be waits and explains but it would be grammatically incorrect to use them in these cases:
✗ It was suggested that he waits till the next morning.
✗ They demanded that the prime minister explains who authorized the action.
Here are the other main uses of the subjunctive:
after if, as if, as though, and unless, in sentences that state a hypothetical condition, or with the verb to wish:
If I were taller, I would have been a model.
I wish I were more confident.
be and were are used at the beginning of sentences or clauses when the subject follows:
Were I to make a list of my favourite films, this would be in second place.
All books, be they fiction or non-fiction, should provide entertainment.
in certain fixed expressions, for example ‘be that as it may’, ‘come what may’, and ‘so be it’.