The subjunctive is used to refer to situations that are not real (but are desirable) or hypothetical situations.
There are two main categories of the present subjunctive: Mandative and Formulaic. Both are realised by the base form of the verb for all person.
The past subjunctive survives only in the form were of the verb BE.
If she were leaving, you would have heard about it
Also possible with indicative.
If she was leaving ...
With all verbs except BE, the negative is made by placing NOT before the subjunctive form
It is essential that this mission not fail
The Committee has decreed that the students be not/not be exempted from college (both positions)
However, with were NOT always follows the verb
If I were not your best friend ...
Mandative Subjunctive
It's the most common subjunctive, it occurs in subordinate that-clauses. The present and past are not distinguishable.
I demand/ed that the board of teachers reconsider its decision
Their requirement is/was that the system work
The that-clause is introduced by an expression of demand, recommendation, proposal, resolution, intention, etc.
Common expressions that introduce a mandative subjunctive
- With verbs : Ask, demand, prefer, suggest, require, command, insist, propose, recommend, request.
I ask (that) you be quiet
We recommend (that) he use a pen
They suggest he wear a tie
He demands she make a cake
I insist (that) they not eat in class
That is optional
- With adjectives: Desirable, best, important, necessary, crucial, vital, imperative, recommended, essential.
It is necessary that he close the door
It is crucial that he behave like an adult
It was essential that she pass the test
It is not important that you be there
- With the verb to let
I won't let my child see violent films
Let him eat some strawberries
Let her play with her friends
Formulaic Subjunctive
- This is used in set expressions chiefly in independent clauses.
Come what may, we will go ahead with our plan
God save the Queen
Be that as it may, we have nothing to lose
- To express a wish
Far be it from me to spoil the fun
So be it
So help me God
God bless you
Other Uses
- Condition and concession
(Even) if that be the official view, I won't endorse it
- Were-subjunctive
Hypothetical or unreal in meaning. Introduced by If, even if, though, as though and after verbs like suppose or wish. It is limited to the one form Were. (Was is used in informal style.)
If I were/was rich, I would buy an electric car
I wish the journey were/was over