Questions & Answers about Der Park ist nahe dem Haus.
Because dem Haus is in the dative case.
In this sentence, nahe works like a word that governs the dative:
Der Park ist nahe dem Haus.
→ dem Haus = dative singular of das Haus.
Roughly: German often uses the dative after certain prepositions or adjective-like words that express a relation in space, time, etc. Here, nahe (near) is one of those words, so the noun that follows goes into the dative: dem Haus, not das Haus.
Traditionally, nahe can take genitive or dative, but usage differs by style:
- Genitive (more formal / written):
- Der Park ist nahe des Hauses.
- Dative (very common in modern usage):
- Der Park ist nahe dem Haus.
In everyday modern German, the dative after nahe is very frequent and fully acceptable.
If you want to sound very formal or literary, you might occasionally see the genitive (nahe des Hauses), but you don’t need it for normal conversation.