In some languages, the inflections of a verb include a large range of special forms which are used typically in subordinate clauses, and are called 'subjunctives'. English has very few such forms and those it has tend to be used in rather formal styles.
- The school requires that all pupils be honest.
- The school rules demand that pupils not enter the gym at lunchtime.
- If Zoë were the class president, things would be much better.
Subjunctive verbs are triggered by adjectives such as necessary, imperative, crucial, or by verbs such as demand, require, insist, etc. When the subjunctive verb has a third person singular subject, it does not take the -s inflection.
- I insist that he leave at once.
- We stipulated that she take a French course.
Many grammarians now take the view that English does not have a subjunctive mood.