The Subjunctive Mood is used in subject clauses after a principal clause of the type It is necessary, It is important, etc. The analytical subjunctive with the mood auxiliary should is used for all persons.

Affirmative Interrogative

It is (was) necessary

It is (was) important

It is (was) right

It is (was) requested

It is (was) recommended

It is (was) obligatory

It is (was) better (best)

It is (was) desirable

It is (was) of vital importance

that he should come

The Subjunctive Mood is used in subject clauses after a principal clause of the type It is necessary, It is important, etc. The analytical subjunctive with the mood auxiliary should is used for all persons.

It was necessary that the child’s history should be known to none. (Trollope)

It was desirable that she… should marry this earnest, well-to-do and respectable man. (Hardy)

It is better for these young men… that they should not remain here. (Dickens)

It was imperative that she should go home. (Hardy)