Question: Who was the speaker that spoke about the Berlin wall and how many siblings did he have?
Answer(s):
answer: John F. Kennedy

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.01qlg1)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.01qlg1 ns:people.person.children ?x .
?x ns:event.public_speaker.speeches_or_presentations ?c .
?c ns:event.speech_or_presentation.speech_topic ns:m.017f5 . 
}