Amoy dialect
They speak Singaporean Hokkien, the standard of which is based on the Amoy dialect of Xiamen, which is partially comprehensible with Teochew although less so with Hainanese. Hokkien Chinese was a "lingua franca" among coastal Chinese and was also used by other ethnic groups such as the Malays and the Indians to communicate with Chinese before Mandarin came to dominance during the 1980s and 1990s.