Le Futur Simple
When to use it:
To describe what will happen at a certain time in the future (equivalent of “will or shall”).
Time phrases: Demain (tomorrow), la semaine prochaine (next week).

Regular Verbs
Regular –er, -ir and –re* verbs all follow the same rules in the future:

1) Take the infinitive (title) of the verb: e.g donner, finir
2) Add the endings     : -ai, -as, -a , -ons, -ez, -ont,
* There is a slight difference for –re verbs. Before adding the endings
you must take off the “e”.
For example:   vendre = vendr

Futur Simple: Irregular Verbs
For irregular verbs in the futur simple, you only need to learn the stem as the endings are the same.