I feel proud to say that I currently know a fusional language (english),  agglutinative language (hindi and tamil) and currently learning a polysynthetic language sanskrit.,(reply>), Sanskrit isn´t a polysynthetic language, that´s the smallest and rarest group of languages, mostly limited to Native Americans (like Tom said, it´s the Algonquian languages, the Inuktitut, some languages of Central America etc.) Sanskrit is fusional. Plus, modern English is more isolational than fusional. So you know isolational, agglutinative and fusional languages 🙂