The subjunctive is very rare in English, and remains in expressions such as
God save the queen, If I were you

The French subjunctive can take these english forms
(that) he may go, (that) he go, let him go

In French, the subjunctive is usually used after the conjunction que, that means that.
It is used in expressions of doubt, necessity, desirabilty, insistance, fear, or some other emotion (sorrow, joy). Here are some of these expressions to be followed by the subjunctive.

To form the present subjunctive, take the present participle (going, singing) and remove the -ant ending. Then add -e for je, -es for tu, -e for il/elle, -ions for nous, -iez for vous and -ent for ils/elles.

Here is the present subjunctive for some common irregular verbs.

To form the past subjunctive, take the present subjunctive form of être or avoir followed by the past participle e.g.

Je sois allé(e)

This takes these English forms
(that) he may have gone, (that) he has gone