The subjunctive mood is used to express actions or ideas which are
subjective or otherwise uncertain: will/wanting, emotion, doubt, possibility,
necessity, judgment. It is nearly always found in dependent clauses
introduced by que or qui, and the subjects of the dependent and main
clauses are usually different.
Verb endings are different to normal, and change
for I, they, she, he, we and us.
There are also irregular verbs which do
not follow the pattern that the other verbs
do.
Je veux que tu le fasses. I want you to do it. Il
faut que nous partions. it is necessary that we
leave.
Elle veut que nous soyons à la fête. She wants
us to be at the party. J'aimerais que vous
m'appeliez demain. I would like for you to call me
tomorrow.
The subjunctive tense isn't a tense in itself, in fact there
is the present subjective tense, and the perfect
subjective tense.
The subjunctive by itself doesn't really carry any particular meaning and generally isn't
used in a sentence on its own. It is always triggered by some other word in the
sentence.
In English, subordinate clauses are usually introduced by words such as that,
which, who, where etc. In French, subordinate clauses are inroduced by words
such as que, qui, où etc. So that means that subjunctive forms in French are
basically always introduced by one of these words.
To conjugate all regular verbs ending -ER, -IR, and -RE, as well
as some irregular* ones, take the 3rd person plural ils form of
the present tense of the verb, drop the -ent ending to find the
stem, and add the subjunctive endings:
Unlike a few tenses in French, there is
no interrogative form of it, which means
less to learn!
All these verbs introduce the subjunctive in the negative, since now the
percentage of chance of the action becoming a reality is very low: Je
pense qu’il reviendra = his coming, to me, has a 90% chance of becoming
a reality = indicative Je ne pense pas qu’il revienne = his coming, to me,
has a 5% of becoming a reality = subjunctive