Learn Hardcore French: Quand tu seras en France, tu t’y habitueras vite, au nord comme au sud. - When you are in France, you will get used to it quickly, in the north as well as in the south.

Why does the sentence use tu seras and tu t’y habitueras (future) instead of the present tense like in English "when you are in France, you’ll get used to it"?

In French, when you talk about a future event introduced by quand (when), you normally use the future tense in both clauses, not the present + future like in English.

So:

Quand tu seras en France = When you are in France (literally: when you will be in France)
tu t’y habitueras vite = you will get used to it quickly

This is a standard rule with quand, lorsque, dès que, aussitôt que, tant que, etc., when they refer to the future:

Quand il arrivera, nous mangerons.
When he arrives, we’ll eat.

Using the present (Quand tu es en France) here would sound wrong if you’re clearly talking about the future.

Why is it en France and not à France?

For countries, French usually uses en with feminine countries (and some others) and au with masculine ones:

en France (feminine)
en Italie, en Espagne, en Allemagne
au Canada, au Japon, au Portugal (masculine)
aux États-Unis, aux Pays-Bas (plural)

You basically never say à France. À is used for cities:

à Paris, à Londres, à New York.

What exactly does y refer to in tu t’y habitueras?

Y is a pronoun that usually replaces à + a thing / a place.

Here it stands for à la vie en France / à la France / à ce pays, i.e. to life there / to that place.

The verb is s’habituer à quelque chose (to get used to something), so:

Tu t’habitueras à la vie en France.
→ Tu t’y habitueras. (You’ll get used to it.)

Because la vie en France is already known from context, French replaces à la vie en France with y.

Why do we have both tu and t’ in tu t’y habitueras? Isn’t one you enough?

They are two different things:

tu is the subject pronoun (the one doing the action)
te / t’ is the reflexive pronoun used with the reflexive verb s’habituer

The infinitive is s’habituer à (to get used to). In the future:

je m’y habituerai
tu t’y habitueras
il/elle s’y habituera
nous nous y habituerons
vous vous y habituerez
ils/elles s’y habitueront

So tu t’y habitueras literally is you yourself to-it will-get-used. French keeps both pronouns.

Why is it t’y and not something like tu y t’habitueras? What’s the rule for the order of pronouns here?

French clitic pronouns follow a fixed order in front of the verb. In this sentence we have:

te (t’) = reflexive pronoun
y = pronoun for à + thing / place

The rule is that me / te / se / nous / vous come before y.
So the only correct order is:

tu t’y habitueras

You cannot say:

✗ tu y t’habitueras
✗ tu habitueras t’y

Those are ungrammatical.

What does s’habituer à mean compared with être habitué à?

Both are related but not identical:

s’habituer à = to get used to (process of becoming used to something)
- Tu t’y habitueras vite.
  You’ll get used to it quickly.
être habitué(e) à = to be used to (result state)
- Tu es habitué à la vie en France.
  You are used to life in France.

So in the original sentence, the idea is about the change over time, so s’habituer is the natural choice.

Could the sentence be Quand tu es en France, tu t’y habitues vite instead?

Yes, but that would change the meaning.

Quand tu es en France, tu t’y habitues vite.
→ General truth / habit: Whenever you are in France, you get used to it quickly.
Quand tu seras en France, tu t’y habitueras vite.
→ One specific future situation: When you’re (next) in France, you’ll get used to it quickly.

So the original uses the future because we’re clearly talking about a future stay in France.

What exactly does au nord comme au sud mean? Does comme here mean “like”?

Here au nord comme au sud means “in the north as well as in the south”, or “whether you’re in the north or in the south”.

au nord = in the north
au sud = in the south
comme here has the sense of “as well as / just like / both … and …”

So the whole sentence means: you’ll get used to life in France quickly, no matter whether you’re in the north or the south. It’s not “like the south”; it’s “as much in the north as in the south.”

Why is it au nord and au sud, not en nord / en sud?

Nord and sud here are treated like regions / parts of a country, not like countries themselves. French usually says:

au nord de la France, au sud de la France
or, when the country is obvious: au nord, au sud, à l’est, à l’ouest

We use à + le = au with these cardinal points.

En is mainly used with countries (en France) or some large regions (en Europe). You would not normally say en nord or en sud in this context.

Can vite be placed somewhere else, or does it have to be tu t’y habitueras vite?

For a simple verb, vite usually comes right after the verb:

Tu t’y habitueras vite.

You can modify it with something like très or assez:

Tu t’y habitueras très vite.
Tu t’y habitueras assez vite.

Putting vite at the very beginning or very end for emphasis is possible but more marked:

Vite, tu t’y habitueras. (sounds a bit literary / stylized)
Tu t’y habitueras, vite. (sounds more like spoken emphasis)

The neutral, standard spot is the one in the original sentence.

How would the sentence change if I used vous instead of tu?

With vous, you need to change both the subject and the reflexive pronoun, plus the verb endings:

Quand vous serez en France, vous vous y habituerez vite, au nord comme au sud.

This is what you’d say to one person formally, or to several people. The structure (future tense, y, au nord comme au sud) all stay the same.

Could I drop en France and just say Quand tu y seras, tu t’y habitueras vite?

Yes, if the context already makes it clear that y refers to France. For example:

Tu vas partir vivre en France. Quand tu y seras, tu t’y habitueras vite.
You’re going to live in France. When you’re there, you’ll get used to it quickly.

In the standalone sentence, Quand tu seras en France is clearer, because the listener might not yet know what y refers to.

Why do we need any pronoun like y there? Could we just say tu t’habitueras vite?

You can say simply:

Quand tu seras en France, tu t’habitueras vite.

That means you’ll get used quickly, but it’s a bit less precise; it doesn’t explicitly say get used to what.

Adding y ties the verb clearly to the idea of that place / that life / that situation previously mentioned:

Quand tu seras en France, tu t’y habitueras vite
→ When you’re in France, you’ll get used to it (life there) quickly.

So y makes the sentence feel more complete and natural in French.