How many {noble title} are for {Louis the Pious} ?
What is the number of kings for Louis the Pious?
How many Kings are for Louis the Pious?
SELECT ( COUNT ( ?x ) AS ?o ) { resource:Louis_the_Pious property:noble_title ?x }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q43974> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P97> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q43974 wdt:P97 ?obj }
4