Recommended Reading
As a French Tutor in North West London I have always been fascinated by the French grammar and its logic that is on the whole so similar to Maths. I find the subjunctive opens up so many possibilities.
Usage
There are many cases but the general and easiest case will be dealt with here.(A lesson will be needed for full details). It can often be used when infinitives in English cannot be used in French where the subject is different. Think of the example "I want to brink". The infinitive can be used in French in the same way as in English as there is only one subject involved here ie "Me".(Je veux boire).
It becomes interesting when one wants to say for example "I want him to drink". There are now two subjects here ie "Him and me". The infinitive now must not be used in French. We now have to translate " I want that he drinks" with one small change beyond that. The subjunctive is used in the subordinate clause "He drinks" but not in the main clause "I want". Therefore, the whole sentence will read "Je veux qu'il boive", instead of "Je veux qu'il boit" (which would be incorrect). The technical reason why a subjunctive is used is because "Wanting" is a wish and therefore the "Drinking" may never be carried out (It is hypothetical). This now leads us to how the subjunctive is formed.
Formation
Apart from the seven irregular or semi irregular verbs in the present subjunctive the rule is as follows:
Take the the "Ils" form of the present tense and remove the "Ent" for the first column only and add the present tense "ER" verb endings. In the second column the "Nous" and "Vous" forms will be identical to the imperfect tense and the "Ils" form will be identical to its present tense counterpart. Here is "Boire" in the present subjunctive:
Je boive Nous buvions
Tu boives Vous buviez
Il boive Ils boivent
Other Tenses
Please note that the imperfect subjunctive and the pluperfect subjunctive are rarely used in conversational French nowadays. If used in writing the past historic tense will need to be used instead of the perfect tense unless the meaning is strictly "Has done" or "Has been doing" instead of "did" for instance or of course if one is quoting what someone else has said in that essay. Therefore, one would use the present subjunctive or perfect subjunctive if required regardless of the tense. A lesson could be arranged to learn these rare subjunctives for A Level and beyond and similarly with the past historic.
