What is the {human} for {sibling} of {Paul McCartney}
What are the names of Paul McCartney's children?
Who are Paul McCartney's sons and daughters.
SELECT DISTINCT ?r WHERE { ?r rdf:type ontology:human . ?r property:sibling resource:Paul_McCartney }
select distinct ?subj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?subj . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P3373> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q2599> . ?subj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q5> } 
 select distinct ?sbj where { ?sbj wdt:P3373 wd:Q2599 . ?sbj wdt:P31 wd:Q5 } 
Mike McGear