Wiktionary says it's the genitive, plural of "der" (which I thought was "deren"). I'm not only unsure how to use "derer" but also, what does it mean. Duden doesn't say too much either. Can somebody shed some light, especially with examples?
but can also be used in sentences where
So it works as a pronoun for something (in this case
For derer, Wiktionary gives only one example, from an AFP news story. Duden lists many more examples but they all (apparently) are made-up, with no surrounding context that could help to understand usage better. On the plus side, the Duden editors attempt to illuminate when derer is correct and when deren should be used instead.
And Digitales Wörterbuch der deutschen Sprache, which can be so helpful when it shows dozens of examples from actual usage in context, this time falls down completely. So you are left to your own devices. That means firing up ye olde search enginne and doing your own legwork. After looking at a couple of dozen examples, you should be able to get a feel for the word.
Right, the grammar. Well, Duden says that it's genitive plural of der, die, das. That is somewhat confusing. You have to click on a link to find that they do not mean the definite article but der, die, das when they function as demonstratives.
Most people steer well clear of using derer, being unsure of its correct application. Instead of
they will look for a construction such as
(This last der, by the way, is the genitive plural of the definite article der, die, das.)
The foregoing does not apply when derer is used as an archaic remnant. Such an example would be
given by Duden. No one talks that way anymore except when they
(a) are quoting from 19th-century novels, or
(b) want to affect a highfalutin' tone:
Approximate English equivalent (stick broomstick up posterior and read aloud):
*identical to nominative plural
Okay, by now you thoroughly hate me, for having filled your head with a mess of stupid detail instead of making the awful German language comprehensible and easy to use. So, forget all of that. There are only three rules. (That's two more than Lt. Jean Rasczak's, but I'm profligate that way.)
(1) Never, ever use derer when speaking or writing.
(2) Bookmark this page and refer back to it when you have the misfortune to encounter derer in a text.
(3) When someone tries to impress you with their refinement by using derer in conversation, LOL @ them.
And there you go. I've done my level best to advise you and other advanced learners of German. If mastery of the German language is a tree, then derer and its uses are the tips of the twiglets of a branch. In my estimation, some 97 percent of Germans do not know at all how to use this demonstrative, or they use it poorly. You would do better to stick to more common alternatives such as derjenigen.