Hanover:

"Hanover" is the traditional English spelling. The German spelling (with a double n) is becoming more popular in English; recent editions of encyclopedias prefer the German spelling, and the local government uses the German spelling on English websites. The English pronunciation /ˈhænəvər/, with stress on the first syllable and a reduced second syllable, is applied to both the German and English spellings, which is different from German pronunciation [haˈnoːfɐ], with stress on the second syllable and a long second vowel. The traditional English spelling is still used in historical contexts, especially when referring to the British House of Hanover.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What does the German spelling of Hanover have that English does not?
a double n