A multitude of languages are used in Singapore. It consists of several varieties of languages under the families of the Austronesian languages, Dravidian languages and Sino-Tibetan languages. According to the Constitution of Singapore, the national language of Singapore is Malay, which plays a symbolic role, as Malays are constitutionally recognised as the indigenous peoples of Singapore, and it is the government's duty to protect their language and heritage. The constitution also states that the four official languages of Singapore are English, Mandarin Chinese, Malay and Tamil, with the lingua franca between Singaporeans of different ethnicities being English, the "de facto" main language.