The native resident in Taiwan province speaks 闽南语 which is one of the Chinese eight phylums. But people in taiwan also speaks mandarin, the same with the people in mainland. Mandarin is the official language of China. Twiwanese is Chinese. Taiwan is a part of China.

of course!just have chinese !only one chinese!chinese speak chinese!no taiwanese!

Only china~! not Taiwanese.

yeah I support there that no politics should be mentioned when we study language. but I also agree that there is not a language called Taiwanese( people there do call themselves by that), they still say it as Mandarin, it is the offical language. But the accent got some slight difference.