Question: Which countries has Tamil as one of their official languages?
Evidence: Tamil (/ˈtɑːmɪl/; தமிழ் Tamiḻ [t̪amiɻ], pronunciation (help·info)) is a Dravidian language natively spoken by the Tamil people of South Asia. Tamil is an official language of the Indian state of Tamil Nadu, the sovereign nations of Sri Lanka and Singapore, and the Indian Union territory of Puducherry. Tamil is also spoken by significant minorities in the four other South Indian states of Kerala, Karnataka, Andhra Pradesh and Telangana, and the Union Territory of the Andaman and Nicobar Islands. It is also spoken by the Tamil diaspora found in many countries, including Malaysia, Myanmar, South Africa, United Kingdom, United States, Canada, Australia and Mauritius. Tamil is also natively spoken by Sri Lankan Moors. One of 22 scheduled languages in the Constitution of India, Tamil was the first to be classified as a classical language of India.

Tamil is one of the longest-surviving classical languages of India. A. K. Ramanujan described it as "the only language of contemporary India which is recognizably continuous with a classical past". The variety and quality of classical Tamil literature has led to it being described as "one of the great classical traditions and literatures of the world". Recorded Tamil literature has been documented for over 2000 years. The earliest period of Tamil literature, Sangam literature, is dated from c. 300 BC until AD 300. It has the oldest extant literature among Dravidian languages. The earliest epigraphic records found on rock edicts and 'hero stones' date from around the 3rd century BC. About 60,000 of the approximately 100,000 inscriptions found by the Archaeological Survey of India in India are in Tamil Nadu. Of them, most are in Tamil, with only about 5 percent in other languages. Tamil language inscriptions written in Brahmi script have been discovered in Sri Lanka and on trade goods in Thailand and Egypt. The two earliest manuscripts from India, acknowledged and registered by the UNESCO Memory of the World register in 1997 and 2005, were written in Tamil.

In 1578, Portuguese Christian missionaries published a Tamil prayer book in old Tamil script named Thambiran Vanakkam, thus making Tamil the first Indian language to be printed and published. The Tamil Lexicon, published by the University of Madras, was one of the earliest dictionaries published in Indian languages. According to a 2001 survey, there were 1,863 newspapers published in Tamil, of which 353 were dailies.

Classification
Main article: Dravidian languages
Tamil belongs to the southern branch of the Dravidian languages, a family of around 26 languages native to the Indian subcontinent.  It is also classified as being part of a Tamil language family that, alongside Tamil proper, includes the languages of about 35 ethno-linguistic groups such as the Irula and Yerukula languages (see SIL Ethnologue).

The closest major relative of Tamil is Malayalam; the two began diverging around the 9th century AD. Although many of the differences between Tamil and Malayalam demonstrate a pre-historic split of the western dialect, the process of separation into a distinct language, Malayalam, was not completed until sometime in the 13th or 14th century.

History

Findings from Adichanallur in the Government Museum, Chennai

Keezhadi excavation site
Tamil, like other Dravidian languages, ultimately descends from the Proto-Dravidian language, which was most likely spoken around the third millennium BC, possibly in the region around the lower Godavari river basin. The material evidence suggests that the speakers of Proto-Dravidian were of the culture associated with the Neolithic complexes of South India.

Among Indian languages, Tamil has the most ancient non-Sanskritic Indian literature. Scholars categorise the attested history of the language into three periods: Old Tamil (600 BC–AD 700), Middle Tamil (700–1600) and Modern Tamil (1600–present). In November 2007, an excavation at Quseir-al-Qadim revealed Egyptian pottery dating back to first century BC with ancient Tamil Brahmi inscriptions. There are a number of apparent Tamil loanwords in Biblical Hebrew dating to before 500 BC, the oldest attestation of the language. John Guy states that Tamil was the lingua franca for early maritime traders from India.

In 2004, a number of skeletons were found buried in earthenware urns in Adichanallur. Some of these urns contained writing in Tamil Brahmi script, and some contained skeletons of Tamil origin.

Between 2017 and 2018, 5,820 artifacts have been found in Keezhadi. These sent to Beta Analytic in Miami, Florida for Accelerator Mass Spectrometry (AMS) dating. One sample containing Tamil-Brahmi inscriptions was claimed to be dated to around 580 BC.
Answer: Tamil is one of the official languages in the following countries and territories. India, Srilanka, Singapore and Indian union territory of Puducherry.