The East Formosan languages consists of various Formosan languages

Formosan languages

The Formosan languages are the languages of the indigenous peoples of Taiwan. Taiwanese aborigines currently comprise about 2% of the island's population. However, far fewer can still speak their ancestral language, after centuries of language shift...

 scattered across Taiwan, including Kavalan

Kavalan language

Kavalan was formerly spoken in the Northeast coast area of Taiwan by the Kavalan people . It is an East Formosan language of the Austronesian family....

, Amis

Amis language

Amis is the Formosan language of the Amis Ami, an indigenous tribal people living along the east coast of Taiwan . It is spoken from Hualien in the north to Taitung in the south, with another population near the southern end of the island, though the northern varieties are sometimes considered a...

, and the extinct Siraya language

Siraya language

Siraya is a Formosan language spoken until the end of the 19th century by the indigenous Siraya people of Taiwan. Dialects of Siraya included Taivoa and Makatao....

. This grouping is supported by both Robert Blust

Robert Blust

Robert A. Blust is a prominent linguist in several areas, including historical linguistics, lexicography and ethnology. Blust specializes in the Austronesian languages and has made major contributions to the field of Austronesian linguistics....

 and Paul Jen-kuei Li

Paul Jen-kuei Li

Paul Jen-kuei Li is a research fellow at the Institute of Linguistics, Academia Sinica in Taipei, Taiwan. Li is a leading specialist on Formosan languages, and has published dictionaries on the Pazih and Kavalan languages.-References:...

. Li considers the Siraya-speaking area in the southwestern plains of Taiwan to be most likely homeland of the East Formosan speakers, where they then spread to the eastern coast of Taiwan and gradually migrated to the area of modern-day Taipei

Taipei

Taipei City is the capital of the Republic of China and the central city of the largest metropolitan area of Taiwan. Situated at the northern tip of the island, Taipei is located on the Tamsui River, and is about 25 km southwest of Keelung, its port on the Pacific Ocean...

 (Li 2004).

Evidence

Li (2004) presents the following criteria as evidence for an East Formosan subgrouping.

1. Merger of *C and *t as /t/
2. Merger of *D and *Z as /r/ or /l/ in Basay, as /z/ in Kavalan
3. Merger of *q, *H, *ʔɦ and ø
4. Merger of *j, *n, and *N as /n/
5. Shift of *k into /q/ and /q/ > /h/ (Basay only) before *a

Li (2004) notes that the split of *k into k and q (before *a) is shared exclusively by Basay and Kavalan. Like Kavalan and Basay, the Siraya language merges the patient-focus and locative-focus forms, although Amis distinguishes the two focus forms. Li also gives scores of lexical innovations shared by the East Formosan languages.

The Basay, Kavalan, and Amis also share an oral tradition stating a common origin from an island called “Sinasay” or “Sanasay,” which is probably the Green Island

Green Island, Taiwan

Green Island is a small volcanic island in the Pacific Ocean, about off the eastern coast of Taiwan. In the 19th century it was known as Samasana Island and the Japanese called it Kasho-to . The island is 15.092 km² at high tide and 17.329 km² at low tide...

 of today.

Ketagalan dialects

Li (1992) distinguishes 6 Ketagalan dialects (alternatively called the "Basaic" group).

• Ketagalan
  • Western
    • Luilang
    • Nankan
    • Puting
  • Eastern
    • Basay
    • (Branch)
      • Trobiawan
      • Linaw

Sirayaic languages

The Sirayaic languages are:

• Siraya
  Siraya language
  Siraya is a Formosan language spoken until the end of the 19th century by the indigenous Siraya people of Taiwan. Dialects of Siraya included Taivoa and Makatao....
  
   — spoken in the coastal area of Tainan Plain.
• Taivuan — spoken mostly in the inland of Tainan Plain to the north (just west of Southern Tsouic territories).
• Makatau — spoken in Kaohsiung and Pingtung Prefectures to the south (just west of Paiwan territories).

Paul Jen-kuei Li (2009) attempted a classification of the three Sirayaic languages Siraya

Siraya language

Siraya is a Formosan language spoken until the end of the 19th century by the indigenous Siraya people of Taiwan. Dialects of Siraya included Taivoa and Makatao....

, Taivuan, and Makatau.

However, Li (2009) found that there were two conflicting trees.

1. Tree based on the number of phonological innovations

• Sirayaic
• *Taivuan
  • Siraya–Makatau
    • Siraya
    • Makatau

2. Tree based on the relative chronology of sound changes

• Sirayaic
  • Siraya
    • Taivuan–Makatau
      • Taivuan
      • Makatau

Li (2009) considers the second tree (the one containing the Taivuan–Makatau group) to be the somewhat more likely one.