Question: Do Prince Harry and Prince William have the same parents?
SPARQL:
PREFIX dbo: <http://dbpedia.org/ontology/> 
ASK
WHERE { 
        <http://dbpedia.org/resource/Prince_William,_Duke_of_Cambridge> dbo:parent ?x . 
        <http://dbpedia.org/resource/Prince_Harry> dbo:parent ?x .
}