How to say I don't understand in Austria

Austria
Capital city:

Vienna (Wien)

National / Official language(s):

German (Austrian german)
Slovenian (Carinthia and Styria)
Croatian (Burgenland)
Hungarian (Burgenland)

Other spoken language(s):

English (Big cities e.g. Vienna, Graz, Salzburg)
Czech (Neighboring country)
Slovak (Neighboring country)

National / mainly used expression(s)

German
Ich verstehe nicht.
I don't understand.
German
Ich verstehe nur Bahnhof.
I don't understand.
German
Ich verstehe das nicht.
I don't understand that.

How to say I don't understand in different countries (languages)

Other expressions and phrases in Austria