In 1939 a language based on Tagalog became this country's official language
The 1973 constitution designated the Tagalog-based "Pilipino", ... it 
was first declared to be the national language of the country, I don't think... [DOC] [TLE] Development of Filipino, The National Language of the Philippines ... [PAR] Apr 29, 2015 ... 1937 stating that the national language will be based on Tagalog.