"y" (there):
* "Y" is a pronoun used to refer to a place already mentioned.
* Example: "Tu es allé chez toi ? Oui, j'y suis allé." (Did you go home? Yes, I went *there*.)
"quand" (when):
* "Quand" refers to time.
* Example: "Quand es-tu arrivé chez toi ?" (When did you arrive *home*?)
How to rephrase your sentence:
To say "is at home since" you need to provide more information. You can use different options depending on the context:
1. "Il/Elle est à la maison depuis..." (He/She is at home since...)
* This uses the preposition "à la maison" for "at home".
* Follow it with the duration (e.g., une heure, deux jours, etc.).
2. "Il/Elle est chez lui/elle depuis..." (He/She is at his/her place since...)
* This uses the pronoun "lui/elle" to indicate possession of the house.
Example:
* Original: "Il est chez toi depuis une heure." (He is at your place since one hour.)
* Rephrased: "Il est chez lui depuis une heure." (He is at his place since one hour.)
Important Note: You can't just replace "chez toi" with "y" or "quand" because they don't carry the meaning of "at home" or "at your place". You need to use a different phrase to express this idea.