Comparitive Syntax of Fijian and Tongan: Research on how a Proto-Central Pacific evolved from an ergative actancy system into modern Fijian which has an accusative one. Comparison is made with Tongan which retains an ergative system.
Evidence for Grammatical Functions in Tongan: A review of open issues in the grammar on Tongan in light of recent developments in grammatical theory and the analysis of Western-Malayo-Polynesian languages.
James & Meliame's Tongasite: This site is primarily in Tongan.
Lea 'O Tonga: Tongan language lessons with many example sentences, very basic grammar and conjugation.
Learn To Speak Tongan: Brief list of basic phrases and words for expressing time.