The simple future

A second future, and the written one. Week 10 gave je vais partir; this gives je partirai.

The stem is the infinitive itself — nothing is removed — and one set of endings is added. They are the present tense of avoir, which is where the tense came from historically and a useful way to remember it.

Verbs in -re drop the final e: prendre → je prendrai, écrire → j'écrirai, dire → je dirai.

The irregular stems are irregular only in the stem — the endings never change, and these ten cover nearly everything:

And il faut → il faudra, which you will need constantly.

Which future to use. Je vais partir is the near future: spoken, close at hand, already decided. Je partirai is the simple future: written, further off, or more formal. In speech the near future dominates; in an announcement, a timetable or a written plan the simple future is what you will read. Neither is wrong for a nearby event, so when in doubt use the one you can form.

Every stem ends in -r. That is the audible signature of the tense — je serai, j'aurai, je ferai — and it is what separates je serai (future) from je serais (conditional, week 23) in writing, though the two sound nearly identical.