Complex sentence: Singaporeans or Singaporean people are citizens of, or identify with, the city-state of Singapore--a multi-racial and multi-cultural country with Chinese, Malays and Indians historically making up the majority of the population.
Split into simpler sentences: Singaporeans or Singaporean people are citizens of, or identify with, the city-state of Singapore. Singapore is a multi-racial and multi-cultural country, with Chinese, Malays and Indians historically making up the majority of the population.