Its purpose was to prepare for the nationwide teaching of the Tagalog-based national language (Wikang Pambansa na batay/base sa Tagalog) by creating a dictionary and a grammar book with a standardized orthography.

The Kinarol-an language Barangay Carol-an, Kabankalan, Negros Occidental was considered as extinct as it was no longer being used in casual conversations.

The study also noted that the Inagtâ Isaróg language of Goa, Ocampo and Tigaon in Camarines Sur had only one remaining speaker in 2015.

[16] Meanwhile, the threatened languages with more than a thousand speakers remaining are Álta Kabulowán of Gabaldon, Nueva Ecija; Ayta Mag-Indí of Pampanga and Zambales; and Gubatnón Mangyán of Magsaysay, Occidental Mindoro.

[16] Those that have lessening usage include Inagta Irayá of Buhi, Camarines Sur; Binaták of Palawan; Manidé of Camarines Norte; Ayta Kadí of Quezon Province; Ayta Ambalá of Zambales and Bataan; Ayta Mag-antsi of Tarlac, Nueva Ecija, and Zambales; Ténap (Agta Dupaningan) of Cagayan and Isabela; Bolinaw of Pangasinan; Agta Dumagat Casiguran of Isabela and Aurora; and Agtâ Dumagat Umíray of Aurora and Quezon Province.

These are Manobo Kalamansíg of Sultan Kudarat; Ratagnón Mangyán of Occidental Mindoro; Îguwák of Nueva Vizcaya; Karáw of Benguet; Tagabulos of Aurora, Bulacan, and Quezon Province; Bangon Mangyán of Oriental Mindoro; Manobo Ilyanen of Cotabato; Gâdang of Mountain Province; Kalamyanën of Palawan; Tadyawan Mangyán of Oriental Mindoro; Finallíg of Barlig, Mountain Province; Menuvú of Bukidnon; Tawbuwíd Mangyán of Occidental and Oriental Mindoro; Manóbo Arománën of Cotabato; Manóbo Tigwahánon of Bukidnon; and Abéllen of Tarlac.

Also listed under threat is the Irungdungan (Agta Isirigan) of Cagayan but the KWF observes a rising number of speakers.

[16] The Commission, with the much-needed cooperation and initiated of provincial and local governments, embarked on a landmark project on language revitalization in Abucay, Bataan in 2018, helping the Ayta Magbukun communities in the town's village of Bangkal through Bahay Wika where young members of the ethnic group are being taught of their language by two elders.

It is often left to the universities to develop their own respective terminologies for each field, leading to a lack of uniformity and general public disuse.

[18] On June 1, 2024, the coalitions of Philippine Federation of the Deaf and Alliance of Concerned Teachers staged a protest-rally at Liwasang Bonifacio against the CFL-Arthur P. Casanova, for the cultural retention of Filipino Sign Language (Republic Act 11106).