When should the subjunctive be used instead of the indicative?

The subjunctive is used when there is an element of doubt or uncertainty expressed in a phrase, for example, “il n’est pas certain que…”, “il n’est pas sûr que…” or “il est douteux que…”. Other subjunctive triggers include judgement, for example, « je suis heureuse qu’il vienne ce soir. » On the other hand, the indicative is used for factual phrases. Moreover, impersonal expressions such as, « il semble que… » «il vaut mieux que… » and «il se peut que… » also take the subjunctive form. Verbs of thinking take the subjunctive in the negative, for example “Je ne crois pas qu’il soit…”.

Finally, “que” often indicates the need for the subjunctive, in phrases such as, “pour que.”, “bien que” and “afin que”. The verbs falloir que and vouloir que always take subjunctive.