Did {Genghis_Khan} {spouse} {Yesui}?
Is it true that the wife of Genghis Khan was called Yesui?
Was Genghis Khan's wife named Yesui?
ASK WHERE { resource:Genghis_Khan property:spouse resource:Yesui }
 ASK { ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q720> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P26> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q4177257>. } 
ASK WHERE { wd:Q720 wdt:P26 wd:Q4177257 }