Did {Nelson_Mandela} {child} {Makgatho Mandela}?
Is Makgatho Mandela the name of Nelson Mandela's son?
Did Nelson Mandela name his son Makgatho Mandela?
ASK WHERE { resource:Nelson_Mandela property:child resource:Makgatho_Mandela }
 ASK { ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q8023> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P40> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q2104774>. } 
ASK WHERE { wd:Q8023 wdt:P40 wd:Q2104774 }