...の + ...の?
Usage
S plain form + の is an informal form of ...のですか, used when conversing with someone you are on familiar terms with.
Examples
どこへ行くの?Where are you off
どうしたの。お母さんがないの。What's up? Mum's not here.
Good to know
のです ✍️ んです 🗣️ are used for emphasizing a cause, reason, logical basis, or other explanation