What does this sentence mean?
- "Besonders wenn die Bekannten des Vaters zu Gast waren, konnte das Essen von einem unermüdlichen Gelächter begeleitet sein, ohne dass ich, der ich die weichliche Hirnmasse so schnell und unzerkaut wie möglich die Speiseröhre hinunterzubringen suchte, begriff, ...,"
What is the der in the bold text trying to refer to? I'm completely clueless why the der is located there.
- What is the difference between Erweiterung, Vergrößerung and Ausdehnung?
The author might like to keep talking in the first person perspective. There's no visible difference in past tense, but in present tense, you'd get "ich, der ich (ver)suche, begreife..." vs. "ich, der (ver)sucht, begreife..." - and that change from "(ver)sucht" (3rd person) to "begreife" (1st person) seems to lack a bit of elegance here, although it would be perfectly fine in a modern text and "ich, der ich..." might come off as too formal or even pompous, unless you're holding a speech.
...which is why I think I'd avoid this construction altogether, e.g. "ohne dass ich, während ich versuchte..., begriff..."; or "Nachdem / Da ich es zwei Stunden lang versucht hatte, wusste ich, dass es unmöglich war" (instead of "[The boss was angry because we still hadn't managed to do it, however] ich, der ich es zwei Stunden lang versucht hatte, wusste...").
...but it seems to me that it makes a difference whether the relative clause is happening at the same time / on the same level as the main clause. "Ich, der selbst drei Hunde hat, bin für ein Hundeverbot in Restaurants" ("I, 'who owns' three dogs myself, support a dog ban in restaurants" = unrelated insertion) to me seems to work better than "Ich, der in das Buch vertieft ist, höre ihn nicht" ("I, 'who is' absorbed in the book, don't hear him" = at the same time). Personally, I'd use the dog sentence myself, but wouldn't even think of phrasing the book sentence like this.
And "ich, der (ver)suche" doesn't work grammatically, because "der" (or "die" for a woman) would always imply 3rd person; so you'd need that second "ich" to change the subject of the relative clause into 1st person. Accordingly: "Du, der/die du (ver)suchst, begreifst...", "Wir, die wir (ver)suchen, begreifen..." etc. ("Wir, die wir uns immer für die armen Menschen eingesetzt haben, verlangen von unserem Koalitionspartner..." "We, who have always taken a stand for the poor, demand of our coalition partner...")
I don't know if the author did it for artistic/stylistic reasons, or if "ich, der [das zu tun] sucht" maybe wasn't even acceptable/natural in those days. (It's clearly an old text, e.g. because of the use of "etwas zu tun suchen" = to strive/attempt to do sth., which is why I added "ver-" in brackets above, to update the wording.)
absolutely correct, although this way of even "Writing", let alone "speaking" is not common any longer in Germany, unless of course, someone as a writer would make it to his own style of writing. If you're a native German speaker, you could possibly appreciate these old writing styles, otherwise....there are so much of other wonderful German literature's available to enjoy while enhancing your German language.
Erweiterung, Vergrößerung and Ausdehnung mean actually pretty much the same, but they come from different verbs or adjectives, so they refer to slightly different actions or attributes (weit (=wide here, not far), weiten (widen), erweitern(extend)/groß/dehnen(stretch)). It mostly depends on the context which one you would use. For example, you could use erweitern and vergrößern with a library, but not ausdehnen. Also, all the words have different secondary meanings apart from simply "enlarging" (the "dynamic" meaning, referring to a process). The "static" meanings (referring to a state or attribute) can be pretty different:
- Vergrößerung (einer Linse/Optik): magnification (of a lens/optic)
- Erweiterung (eines Programms): extension (of software)
- Erweiterung (eines Organs): dilation (of an organ)
- Ausdehnung (einer Fläche, eines Gebiets): extention, dimensions (of an area)