Subjunctive Mood

If a sentence expresses a subjective statement of opinion, the subjunctive mood is used.  The subjunctive is used in dependent clauses introduced by the word que.  The main clause must express personal opinions or feelings and have a different subject from the dependent clause.  If the two subjects are the same, the infinitive is used.

Je doute que la situation soit juste.  I doubt that the situation is just. (shows judgment and opinion)
Tout le monde veut que venir.  NOT: Tout le monde veut que tout le monde vienne.  (use infinitive, same subject)

To form the subjunctive, use the ils/elles form of the present indicative tense.  This is also the form for the ils/elles form of the subjunctive.  For je, tu, il/elle, drop the -ent and add -e, -es, and -e.  Nous and vous use the imperfect forms.

Irregular Forms

Here is a list of common expressions that are followed by the subjunctive:

However, douter, jusqu'à ce que, à moins que, and bien que / quoique use the subjunctive whether there is a change in subject or not.  And when using avant before an infinitive, the construction is avant de + infinitive.  Note, also, that the subjunctive is not used with espérer or il est probable, although the subjunctive may be used with these words in other Romance languages.  For some reason, this is not the case in French.

Possessive Pronouns