This is a comprehensive description of Northern Subanen, an Austronesian language spoken by approximately 30,000 people living in the interior mountains of the north-eastern portion of Zamboanga peninsula in Mindanao, the Philippines. It analyses a Philippine-type Austronesian language using basic linguistic theory. After giving a summary of the phonology, it defines the category ‘word’ in the language and discusses the word classes identified on language internal grounds. It recognises a distinct adjective class, explaining its properties in detail. The demonstrative class is also discussed in depth. A number of chapters are dedicated to explore the morpho-syntactic possibilities of a dozen semantic classes of verbs. Verbs are shown to have high propensity to change valency and/or rearrange arguments and syntactic functions. Basic verbal clause structures serve as templates for derived constructions and basic verbal affix forms are recycled for derivational functions. Active verb morphology marks syntactic transitivity. Only about one percent of mono-clausal verbal constructions would be headed by serial verbs. Pivot constraints in SVCs and other attested instances of syntactic ergativity are discussed; also examined is core argument marking, which displays morphological ergativity. Imperative, subordinate and conjoined constructions are dealt with in depth. The description concludes with a typological profile of the language.