In English there are three different relative pronouns
Antonio Buero Vallejo, who
is the most famous Spanish dramatist of post war time,
died in 2000.
The book, which was written
by Antonio Buero Vallejo, was very interesting to read.
The film, which adapted the book by Antonio Buero Valejo,
was done very well.
The German only has two types of relative pronouns.
The first one, der, die, das
etc. we have already presented. These relative
pronouns are identical to the demonstrative pronouns
der, die, das.
The other type is welcher, welche,
welche is identical to the interrogative pronouns
welcher, welche, welches.
There is actually no difference between these two types,
just that der, die, das
is used much more frequently than welcher,
The declination of welcher,
The logic is the same as with der,
Let's have a look at an example
we have two phrases
Das Buch ist langweilig.
= The book is boring
Ich lese das Buch.
= I'm reading the book.
These two phrases shall be combined to one
phrase The book, that I'm
reading, is boring.
The main phrase is Das Buch
ist langweilig. The object the relative pronoun
is referring to is das Buch.
is singular neutral. In the main phrase das
Buch is in Nominative, but that is not too interesting.
That what's interesting is the declination of the relative
phrase. In the relative clause das
Buch is in Accusative -declination.
lese das Buch. Was (oder wen) lese ich? Das Buch. = I'm reading the
book. What do I read? The book.
So we need the relative pronoun in neutral singular
and in Accusative -declination and this is - according
to our table, welches. The phrase is: