As Taipei subway trains pull to a stop, passengers hear a soft female voice announce the name of the next station in three Chinese dialects.
First is Mandarin, the official tongue used by mainlanders who fled to Taiwan with the defeated Chinese Nationalist army after they lost a civil war to the communists in 1949.
Next is Taiwanese, or Hokkien, the dialect of 65 to 70 percent of the population. They hail from China's coastal province of Fujian but feel few links to the homes of ancestors who immigrated in the last four centuries.
Last comes Hakka, one of the smallest Chinese ethnic minorities and accounting for 20 percent of Taiwan's 23 million people.
People usually take scant note of such ethnic differences. But the issue of identity is to the fore just days before a closely fought presidential election on March 20.
ARE WE CHINESE OR ARE WE TAIWANESE? The answer may determine if President Chen Shui-bian, who has fought to establish a Taiwan identity separate from China, wins a second term or is toppled by opposition Nationalist candidate Lien Chan.
"We think the number of Taiwanese supporting the candidacy of Chen Shui-bian is growing," said Lin Wei-kuo, a pollster at Fu-Jen Catholic University, after Chen rallied two million people on February 28 - the anniversary of a 1947 violent crackdown by Nationalist troops against a demonstration by Taiwanese.
Since Chen's Democratic Progressive Party (DPP) was founded as an opposition group in 1986, politics has been polarised along ethnic lines with DPP politicians cutting their teeth on the mostly mainland-born Nationalists who ruled until 2000.
Many Taiwanese viewed mainlanders as the latest in a long string of outside occupiers - from the Spanish and Dutch in the 17th century to the Japanese who took Taiwan as a war indemnity from China's tottering Qing dynasty in 1885.
"Taiwan does have an ethnic identity issue and it's quite serious. It's an important issue at election time," said Larry Huang, a 27-year-old Taiwanese banker who voted for Chen when he won four years ago.
After Nationalist Generalissimo Chiang Kai-shek fled to the island with more than a million soldiers, bureaucrats and merchants, he imposed martial law and restricted the use of the Taiwanese and Hakka dialects for nearly 40 years.
Until martial law was lifted in 1987, the Nationalists brooked no defiance and thousands of intellectuals and activists were imprisoned in what Taiwanese call the White Terror.
"The tragedies of history can be forgiven, but they cannot be forgotten," said Chen's running mate, Vice President Annette Lu. She calls the election a battle between a Taiwanese party and a Chinese party.
Although Chen has vowed to promote ethnic harmony and said he will not change the island's name from the Republic of China to Taiwan, playing the Taiwan identity card has helped his campaign.
The pro-independence president has focused his re-election on a provocative claim that Taiwan is a separate country from China, which views the island as a breakaway province.