What is the first language of Sri Lanka?

Sinhala is an Indo-Aryan language primarily spoken by the Sinhalese people of Sri Lanka, who make up the largest ethnic group on the island, numbering about 16 million. Sinhala is also spoken as the first language by other ethnic groups in Sri Lanka, totaling about 4 million people as of 2001. It is written using the Sinhala script, which is one of the Brahmic scripts; a descendant of the ancient Indian Brahmi script closely related to the Kadamba script.

The oldest Sinhala Prakrit inscriptions found are from the third to second century BCE following the arrival of Buddhism in Sri Lanka, while the oldest extant literary works date from the ninth century. The closest relatives are the Vedda language (an endangered, indigenous creole still spoken by a minority of Sri Lankans, mixing Sinhala with an isolate of unknown origin and from which Old Sinhala borrowed various aspects into its main Indo-Aryan substrate), and the Maldivian language.