- Joined
- Jul 28, 2009
- Member Type
- English Teacher
- Native Language
- British English
- Home Country
- UK
- Current Location
- UK
Below: John lives in the apartment below.
Your sentence is correct (if you capitalise "John" because it's a proper noun and the first word of the sentence) but you might need to clarify what the apartment is below. If the listener/reader already knows what you're referring to, it's fine.