Explanation: The Austro-Hungarian Empire was a multiethnic empire of the 19th and early 20th century AD, emphasis on ‘multi’. It was not a particularly well-put-together polity, and relied mostly on dynastic loyalty in a time when nationalism, especially linguistic nationalism, was all the rage. As such, they lacked the ability to impose a common language on the Empire, even for practical purposes like military service, as any attempt to create a base of German (or any other imposed language) speakers would have been seen as an attempt to begin squeezing out the very existence of the local languages - dissent which the Austro-Hungarian Empire could not afford to endure from its vast minority populations if it wished to continue holding those lands!