Favorlang is a Formosan language formerly spoken in the central-western plains of Taiwan. There are a few written documents by Dutch missionaries in the 17th century. It has some interesting grammatical features, not found in other Formosan languages, such as the reverse order of the infixes -um- and -in-, and the same set of personal pronouns may function as either nominative or oblique.
In this paper I discuss the value of the written documents for Favorlang, the linguistic position of Favorlang, problems of interpreting the orthography as used by the Dutch missionaries, and the sound changes that have taken place in Favorlang. In addition, I give a grammatical sketch, including the personal pronouns, case markers, focus, and tense and aspect in Favorlang.