der/die/das as relative pronouns
They agree in gender and number with the noun.
| Case | Masc. | Fem. | Neut. | Plural |
|---|---|---|---|---|
| nominative | der | die | das | die |
| accusative | den | die | das | die |
| dative | dem | der | dem | denen |
| genitive | dessen | deren | dessen | deren |
The relative pronoun's case = its function inside the relative clause.
A relative clause is subordinate.