Subjunctive is seen as a C level task on the exams.  Knowing some phrases can boost your score from an A to a B and if you know them well, achieving a C or E is possible.  This aid memoire will give you clues to the most common uses on the exam.  There are many more, but these extra uses are more for someone learning French literature—we just want a good grade on the exams.

Subjunctive is used when:

1. When there is a mood expressed such as uncertainty, hope, fear, desire, a wish, or a need.
2. Certain expressions are used.
3. When there is only a chance (say 70% or less) that an action could become a reality (e.g. Il est possible que…/it is possible that compared to Il est probable que…/it is probable that…  The first phrase is less likely, so will use subjunctive while there is a higher probability so the present tense is used).  This can happen in the negative as well such as “Je ne pense pas qu’ils viennent”/I don’t think they are coming.
4. Some desires noted in the negative may require subjunctive.  For instance, if we think the probability of something is very low we might say “Nous ne pensons pas qu’elle vienne/We do not think she will come.”  This is different from “Nous pensons qu’elle ne viendra pas./We think she will not come.” which uses the future.  The difference here is that we are thinking that she will not come in the first phase, there is uncertainty here whereas in the second phrase we are thinking with certainty and then using the future tense.  This type of question is C and E level grammar and may only appear on the last third of the exam.

Hints

1. If you see a phrase such as Il faut que…, this construction can use the subjunctive when there is the third person (il/elle) + a conjugated verb + que.  While this is not always the case, it is a clue to check for subjunctive.
2. Certain verbs indicate that the subjunctive is possible including: Falloir (e.g., il faut).  This is not to say that the subjunctive is always used, just that you should double check the context of the phrase for a desire, mood, or feeling.
3. Note that after que, the subject most often changes
4. Ensure you understand the time context of the phrase regarding when in time the actions are occurring as some phrases will use subjunctive in the present tense but if the future is being discussed, they may use a future or conditional tense.

The following is a list of subjunctive phrases that can be seen on the test.  Note the constructions.