A practical english grammar - Vyssaja skola 1978
VERBS of COMMANDING + THAT-cIause with BASE-FORM VERB
Sound symbols
When the characteristic verb expresses the idea of commanding, wishing, ordering, etc., following thut-clauses have a peculiar verb construction (sometimes called the English subjunctive): the base form of the verb is the only one used, and the negative is formed by putting not before it. The auxiliary do is never used.
The judge ordered that the courtroom be cleared.
I recommend that you not wait any longer.
He demanded that we pay the bill at once.
When insist is used in this pattern, the following clause expresses a desire on the part of the speaker. Notice the difference in meaning in the two sentences below.
Mr. Parker insists that his son not smoke. (Mr. Parker does not want his son to smoke.)
Mr. Parker insists that his son does not smoke. (Mr. Parker disagrees with those who say that his son smokes; he says that their information is inaccurate.)
Many verbs in this pattern can also be followed by noun + infinitive, with little difference in meaning. When this is so, the infinitive construction is preferred, since the that-clause is extremely formal.
I prefer him to do it. (Instead of: I prefer that he do it.)
The general ordered us to wait. (Instead of: The general ordered that we wait.)
A comparable use of the subjunctive is seen after phrases with important and necessary.
It’s important that you be on time.
It is necessary that he stay at home.