USE OF THE SUBJUNCTIVE
139. (a) The Subjunctive Présent (3rd pers. sing. and plur.) is very often the équivalent of the English imperative form for the respective third person (see p. 68, No. 9)..
(6) Noun clauses following a verb expressing necessity, regret, doubt, pleasure, command, and désire require the subjunctive for the verb of those noun clauses, e.g.:
il faut que je sois à la maison (it is necessary for me to
be at home) (p. 198, No. 763; see also No. 764) c'est dommage que vous ne soyez pas avec nous (it is too
bad that you are not with us) je veux que vous assistiez avec moi à la soirée (I want you to be présent with me at the function) (p. 169, No. 582)
(c) After prépositions denoting purpose, such as pour que, the subjunctive is required, e.g.} p. 217, No. 855 and 856.