Question: What movie directed by John Singleton did Tupac star in?
Answer(s):
answer: Poetic Justice

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.07pzc)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.07pzc ns:film.actor.film ?y .
?y ns:film.performance.film ?x .
?x ns:film.film.directed_by ns:m.014gc6 . 
}