Question: What nation where German was the official language had as its capital city East Berlin?
Answer(s):
answer: East Germany

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.04306rv)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.04306rv ns:language.human_language.countries_spoken_in ?x .
?x ns:location.country.official_language ns:m.04306rv .
?x ns:location.country.capital ns:m.02lcc . 
}