... but adding another language using the standard SPARQL syntax doesn't work.
How are you doing that? This works:
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
SELECT DISTINCT ?RegionIT ?label (lang(?label) as ?label_lang) ?ISO_code ?Geo
{
?RegionIT wdt:P31 wd:Q16110;
wdt:P300 ?ISO_code;
wdt:P625 ?Geo ;
rdfs:label ?label
}
order by ?RegionIT
Link to try query
To limit to just Italian and English filter on the lang:
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
SELECT DISTINCT ?RegionIT ?label ?ISO_code ?Geo
{
?RegionIT wdt:P31 wd:Q16110;
wdt:P300 ?ISO_code;
wdt:P625 ?Geo ;
rdfs:label ?label
filter(lang(?label) = 'it' || lang(?label) = 'en')
}
order by ?RegionIT
Link to try query
Obviously that multiplies the number of results, one for each language. If that's an issue you can do:
...
rdfs:label ?label_it , ?label_en
filter(lang(?label_it) = 'it' && lang(?label_en) = 'en')
...
which is effectively what the language service does.