Questions & Answers about Der Unterschied ist deutlich.
Because Unterschied has masculine grammatical gender in German. Every noun has a fixed gender that you must learn with the word:
- der Unterschied – masculine (the difference)
- ein Unterschied – a difference
There is no logical rule that says Unterschied must be masculine; it’s simply a vocabulary fact. A good habit is always to learn nouns with their article, e.g. der Unterschied, die Frage, das Problem.
In Der Unterschied ist deutlich., der is in the nominative case.
Reason:
- The subject of the sentence is der Unterschied.
- After the verb sein (to be), the subject is in nominative.
- So we use der (nominative masculine singular), not den (accusative) or dem (dative).