How is the subjunctive formed and when is it needed?

The subjunctive mood is an incredibly useful tool, as using it correctly allows you to access the higher bands of marks for Language Complexity both in essays and oral examinations. Simply put, the subjunctive is needed to express uncertainty or impossibility, emotions and desires where there is a change of person (e.g. Je ne crois pas qu'il soit possible - "je ne crois pas" triggers the subjunctive because it shows uncertainty). To form the subjunctive (for regular verbs), take the present tense 3rd person plural form of the verb, remove the -ent, and add subjunctive endings: e.g. Finir -  je finisse  tu finisses  il finisse      nous finissions   vous finissiez       ils finissent.  Notable Irregular Verbs in the Subjunctive: Etre - sois, sois, soit, soyons, soyez, soient   Avoir - aie, aies, ait, ayons, ayez, aient   Vouloir - veuille, veuilles, veuille, voulions, vouliez, veuillent