How many {depends on software} are to/by {PHP} ?
PHP is the programming language for how many software programs?
How many software programs are written in PHP?
SELECT ( COUNT ( ?o ) AS ?w ) { ?o property:depends_on_software resource:PHP }
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/P1547> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q59 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1547 wd:Q59 }
64