French Y – Adverbial Pronoun

https://www.lawlessfrench.com/grammar/y-adverbial-pronoun/

Y – Adverbial Pronoun

Pronom adverbial

The adverbial pronoun y can replace a place or the object of the preposition à. Y is most commonly equivalent to "there," but may also be translated by a preposition plus "it."

Par exemple…

Nous allons à la plage. Alix nous y attend.   We’re going to the beach. Alix is waiting for us there.
Le travail sera terminé, tu peux y compter.   The work will be done, you can count on it.

Using y

1) Y replaces preposition + place

Y most often replaces a preposition of place, such as à, chez, dans, en, or sur, as well as the place itself.

Par exemple…

Je veux retourner en France. J’y étais l’année dernière.   I want to go back to France. I was there last year.
Il est chez le médecin, il y va le mardi.   He’s at the doctor’s; he goes there on Tuesdays.

2) Y for obvious or implied places

Y can refer to a place that is obvious or implied, even if not preceded by a preposition:

Par exemple…

Restez-y.   Stay there.
J’aime la France, j’y vais chaque année.   I love France, I go there every year.
 

  In English, you can say "I’m going!" and no one will bat an eye. But in French, Je vais ! is not enough; the person you’re talking to will be waiting for you to finish your sentence. If you’re not going to specify the place, e.g., je vais en France, you have to say j’y vais.

3) Y with verbs

Y is also used with verbs that require the preposition à plus an indirect object.

Par exemple…

Je pense à ta décision. J’y pense tout le temps.   I’m thinking about your decision. I think about it all the time.
Répondez au téléphone, répondez-y !   Answer the phone, answer it!