welchem

welchem

"Welchem" means "which" in the dative case.

The word 'welchem' here functions as a dative interrogative pronoun asking about the specific house.

In welchem Haus wohnst du?

In which house do you live?

'Welchem' is used as a relative pronoun in the dative case referring back to the word 'Tag.'

Ich erinnere mich an den Tag, an welchem wir uns kennenlernten.

I remember the day on which we met.

Here, 'welchem' is a relative pronoun in the dative case referring to the noun 'Buch.'

Er hat das Buch gelesen, in welchem die Geschichte beschrieben wird.

He read the book in which the story is described.