Here's why:
* "Ou" means "where" and is used for locations.
* "Est-ce" is the interrogative form of "être" (to be).
* "Habite" is the third person singular present tense of "habiter" (to live).
To make a correct question, you need to restructure the phrase. Here are a few options:
1. "Où habite-t-il/elle ?" (Where does he/she live?)
* This is the most common and grammatically correct way to ask this question.
2. "Où est-ce qu'il/elle habite ?" (Where does he/she live?)
* This is another correct form using the "est-ce que" construction, which emphasizes the question.
3. "Quel est son adresse ?" (What is his/her address?)
* This is an alternative way to ask about someone's residence.
Remember to use the correct subject pronoun (il/elle) depending on who you are asking about.