Which tense of the subjunctive should I use if I am referring to the future?

As there is no 'future subjunctive' in French, the present subjunctive will be used (where required) in a sentence when making reference to future actions (either in the future or conditional tense).

It is also important to note that when using the subjunctive in reference to past actions, the present subjunctive is still used in the vast majority of cases (unless the context is formal written French). For example, a common error is to link the imperfect tense with the imperfect subjunctive - the latter is considered to be outdated in spoken and everyday written French.