During the decades when Germany was split into two independent countries, did their languages develop any differences? I refer only to differences in standard German specifically due to limited communication (books, TV, movies) between the two German countries, and not to the normal differences in regional varieties of German, which I assume were present both before and after the separation.
For East Germany, there are several references to ideas and concepts that have become obsolete as well as slightly different terminology for a single relation. There are several East German peculiarities just as there are several West German peculiarities. Of course, many of these peculiarities developed in East Germany because mainly, the wall caused differences in economic and social statuses. For example, references to specific items and locations can only found in East Germany because West Germany simply had things that East Germany did not. Also, the Russian language and ideals heavily influenced East Germany as it was the USSR's zone. However, a lot of the different styles of language have begun to or have already merged so that both country's language changed to become a more singular entity. An important piece information to note is that East and West Germany was only there for 41 years before they reunified. It might seem like a long time, but in reality, that is an incredibly short time for a country to exist. As a result, no extreme differences developed between the two languages. To sum it up, the major differences between the two are more politically charged where it is a result of differing outlooks on a singular idea, topic, etc. Their minor differences are simply names and references. For a frame of reference, I got several of these differences when I did a study abroad in Germany where one of my host parents was from East Germany and the other one was from West Germany.
Here are a few interesting posts that highlight reasons and gives an explanation to this question for further clarification:
*This is a PDF document but I think it is very good - https://www.leeds.ac.uk/arts/download/1348/braber2004
Some example words adapted from Russia: https://www.jstor.org/stable/1316506?seq=1#page_scan_tab_contents
I hope this helps!
This is an extremely broad question and most probably cannot be answered in full here - As it tends to ask for a definition "what is a language?" as well - Are we "measuring" language by official statements of state and administration? The language used at work, in offices, newspapers, TV? Or by 'normal' conversation when people are simply buying some rolls at the bakery or even private family conversation at home?. The amount of difference between DDR and BRD language usage varies widely between those areas (very probably in descending order of my examples).
Obviously, "official language" was different - There needed to be words for stuff that is only present in socialistic societies like "Kollektiv", "Plan",... that were not present or present in different meanings in West Germany. If you disregard socialistic propaganda and ignore such differences in vocabulary for stuff that simply didn't exist in the West and thus didn't need a notation, a lot of language differences vanish into nothing.
On the other end of the scale there are more regional differences in language and have no "socialistic connotation" - "Broiler" is one of those that comes to mind (even if this has its origin in a socialistic language accident - look it up, it's funny).
When looking at vocabulary imported from the USSR into DDR, my impression is the language influence the USSR had onto East Germany was much smaller than the influence English had onto West Germany - There are way more Anglicisms in German that were imported during the separation than words imported from Russian - "Soljanka" and "Kosmonaut" come to mind, and not a lot more.
Something that really striked me in the 90ies was discussion culture - Expressing an opinion is something that was much more direct and straightforward in West German discussion culture - East German people tended to use subjunctive and defensive language in discussions ("Ich möchte meinen...", "Ich würde sagen...") - which was often considered as "of low self-esteem" and "vague" on the western end of discussion, while BRD language culture occurred to me as much more direct ("Ich sage,...", "ich behaupte,...") - which was often perceived as "arrogant" ("Besser-Wessi") on the eastern end.