Question: What country where Spanish is the main language has a capital city called Quito?
Answer(s):
answer: Ecuador

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.06nm1)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.06nm1 ns:language.human_language.countries_spoken_in ?x .
?x ns:location.country.official_language ns:m.06nm1 .
?x ns:location.country.capital ns:m.01dtq1 . 
}