Relative pronouns and their German declension

There are many relative pronouns in German, some of which agree in gender and number, and are used according to their function in a phrase or sentence.

The pronouns der, die, das

These pronouns agree in gender and number with their antecedent. Their declination depends upon their relative function.

  Masculine Feminine Neutral Plural
Nominative der die das die
Accusative den die das die
Dative dem der dem denen
Genitive dessen deren dessen deren
  • Der Mann, mit dem du damals arbeitetest.
    Dem is singular because it refers to Mann and dative because it follows the preposition mit.
  • Petra, deren Bruder bei uns arbeitet, wartet im Vorraum.
    Deren is feminine singular as it relates to Petra, and genitive because it has a genitive function.

The pronouns welcher, welche, welches

  Masculine Feminine Neutral Plural
Nominative welcher welche welches welche
Accusative welchen welche welches welche
Dative welchem welcher welchem welchen

These pronouns are alternatives to der, die, and das, however they are fairly rarely used.

The pronouns wer and was

  Masculine Feminine Neutral
Nominative wer wer was
Accusative wen wen was
Dative wem wem wem
Genitive wessen wessen wessen

The relative pronouns are used when the person is undetermined.

Interrogative pronouns

Warum? Was? Wann? Wie?
Why? What? When? How?
In this category are wo, wohin, woher, and all other compounds worauf, wozu, etc.
They are formed along the formula of wo + preposition or wo + r + preposition
  • Ich weiß, wo Katrina wohnt. (I know where Katrina lives.)
  • Das ist das Projekt, worum ich mich gekümmert habe. (That is the project with which I was involved.)