what language do the austrians speak
Other languages in Vienna. English is the number one foreign language Austrians learn and speak, but you may come across people who understand at least basic Spanish, French, or Italian too. However the prevalence of these languages is much lower among Austrian population compared to the prevalence of English. While not that much spread in Vienna, Italian is widely spoken in the southern regions of Austria (Styria, Carinthia, and Tyrol).
Obviously, people reading this sort of information in German - mostly Austrians, or Germans and Swiss, or people who have learnt German as a foreign language are likely to approach theses questions from a different angle than people who do not read or speak German.