How many {participant of} are to/by {Spanish Civil War} ?
The Spanish Civil War had how many participants?
How many participants were part of the Spanish Civil War?
SELECT ( COUNT ( ?m ) AS ?g ) { ?m property:participant_in resource:Spanish_Civil_War }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1344> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q10859 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1344 wd:Q10859 }
12