What is {number of speakers} of {Polish} that is {point in time} is {2007-1-1} ?
What number of people spoke Polish on 1-1-2007?
How many speakers were Polish on 1-1-2007?
SELECT ?w WHERE { ?t property:number_of_speakers ?w . resource:Polish property:number_of_speakers ?t . FILTER ( CONTAINS ( YEAR ( ?v ) , '2007' ) ) . ?t property:point_in_time ?v }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q809> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1098> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P585> <2007-1-1>
} 

SELECT ?obj WHERE { wd:Q809 p:P1098 ?s . ?s ps:P1098 ?obj . ?s pq:P585 ?x filter(contains(YEAR(?x),'2007')) }