Learn Hardcore French: Nous y retournons demain, tandis que ma tante reste à la maison. - We are going back there tomorrow, whereas my aunt is staying at home.

Y replaces a previously mentioned place (often something like à Paris, dans ce parc, là-bas) and means roughly there. Example: Nous retournons à Paris demain → Nous y retournons demain. It can also replace some non-person complements introduced by à (e.g., penser à ça → j’y pense), but not people.

Where does y go in the sentence?

With a conjugated verb: before the verb → Nous y retournons.
With a compound tense: before the auxiliary → Nous y sommes retournés.
With an infinitive: before the infinitive → Nous allons y retourner.
Negation: ne
- y before the verb → Nous n’y retournons pas.
Affirmative imperative: after the verb with a hyphen → Retournons‑y. Negative imperative: before → N’y retournons pas.

Can y replace a person?

No. For people, use:

Indirect object pronouns with verbs like parler à: Je parle à ma tante → Je lui parle, not J’y parle.
Or use chez + stress pronoun/name for location: Je vais chez elle, not J’y vais if you want to emphasize it’s her place.

Why use retourner here and not revenir or rentrer?

retourner: go back to a place where the speaker/subject is not currently located. That fits a trip back to some other place: Nous y retournons.
revenir: come back to where the speaker (or reference point) is: Il revient ici.
rentrer: go back home/back inside/return to one’s base: Elle rentre à la maison.

Why is the present tense used with demain?

French often uses the present for near-future plans when a time marker is present: Nous y retournons demain = we’re going back there tomorrow. You could also use:

Futur proche: Nous allons y retourner demain.
Futur simple: Nous y retournerons demain.

Could I use the future instead to make it crystal clear?

Yes. Both are fine:

Nous allons y retourner demain. (futur proche)
Nous y retournerons demain. (futur simple)

Does demain apply to the second clause too, or only the first?

By default, readers understand both actions happen tomorrow: you go back there while your aunt stays home tomorrow. For extra clarity, you can repeat the time or use the future: … tandis que ma tante restera à la maison (demain).

What’s the nuance of tandis que compared with alors que and pendant que?

tandis que: while/whereas, often highlighting contrast between two simultaneous facts (takes the indicative).
alors que: very close to tandis que; also contrasts.
pendant que: purely temporal, means during the time when, with little or no contrast. All three take the indicative.

Is the comma before tandis que required?

Not strictly. It’s common and helpful to mark the contrast: …, tandis que … Without a comma is also acceptable in short, clear sentences.

Can I say On y retourne demain instead of Nous y retournons demain?

Yes. On is very common in speech for we. Conjugation changes to 3rd person singular: On y retourne demain. Nous sounds a bit more formal or emphatic.

Why is it ma tante, not mon tante?

Because tante is feminine, so you use ma. You switch to mon before feminine nouns starting with a vowel sound for ease of pronunciation (e.g., mon amie), but tante starts with a consonant, so it stays ma tante.

What’s the difference between à la maison and chez elle?

à la maison = at home (generic).
chez elle = at her place/at her home (explicitly her home). Both work here: … tandis que ma tante reste à la maison / reste chez elle.

Could y refer to à la maison in the second clause?

It could, if à la maison had already been established as the location in context: … tandis que ma tante y reste. In the given sentence, y refers to some other place, so repeating à la maison avoids ambiguity.

How do I negate the first clause with y?

Place ne before y and pas after the verb:

Nous n’y retournons pas demain. Other negatives work the same: Nous n’y retournons jamais / plus / guère.

Which auxiliary does retourner take in the passé composé?

Intransitive (go back): auxiliary être → Nous y sommes retournés. Past participle agrees with the subject.
Transitive (turn something over/return something): auxiliary avoir → J’ai retourné la crêpe / le paquet. Agreement follows direct-object rules.

Is Nous retournons‑y demain correct?

No. In statements, y must come before the conjugated verb: Nous y retournons demain. The post‑verb hyphen only appears in the affirmative imperative: Retournons‑y.

Can I move demain to a different position?

Yes. Common options:

Demain, nous y retournons.
Nous y retournons demain.
With more detail: Nous y retournons demain matin.

Any pronunciation tips?

Nous y has a liaison: pronounce it as nou‑zi.
tandis que: often said tan‑di kə (final s usually silent before a consonant).
maison: pronounce the s as z: mè‑zon.

Why not simply reste maison?

In standard French you need the preposition and article: rester à la maison. Nouns typically take an article, and à is required to express location here.