Subjunctive in that-clauses
The subjunctive is the simple form of a verb. Examples are: insist, recommend, pay, leave etc. Remember that when you use the subjunctive, there is no –s in the third person singular.
The subjunctive verbs are used to express ideas such as importance or urgency.
I insist that you leave at once.
I suggest that she consult a doctor. (NOT I suggest that she consults a doctor.)
The negative forms are made by putting not before the simple form of the verb.
I recommend that she not accept that job.
(NOT I recommend that she does not accept that job.)
Passive subjunctive verbs are made by putting ‘be’ before the past participle form of the verb.
It is essential that she be told the truth.
Note that even when the verb in the main clause is in the past tense, the subjunctive verb will remain in its simple present tense form.
The judge recommended that he remain in prison for at least seven years.
Common words and expressions followed by the subjunctive are: ask, advise, demand, propose, insist, request, recommend and suggest, essential, important, imperative, critical, vital, necessary etc.
In a less formal style, we are more likely to express the ideas with should + infinitive. This structure is more common in British English.
The judge recommended that he should remain in prison for at least seven years.
She insisted that she should be paid at once.
I insisted that he should leave my room.
It is essential that everybody should have the same opportunities.