On the face of it, Tainan is ethnically homogeneous. Almost everyone, it seems, is descended from Han Chinese who came to Taiwan two or more centuries ago. That's what most people believe, anyhow. The leaders of the Xinhua-based Siraya Culture Association think otherwise, arguing that many Tainan folk are indigenous even if they don't know it.…You won't hear Siraya spoken in Xinhua, but here are a few words to impress - or baffle - the locals: tabe is hello; tatalag means welcome; alid means god, while alilid means to thank.