Estonian (eesti keel) is the official language of Estonia, spoken by about 1.1 million people in Estonia and tens of thousands in various émigré communities. It is a Finno-Ugric language and is closely related to Finnish.
One distinctive feature that has caused a great amount of interest in linguists is that Estonian has what is traditionally seen as three degrees of phoneme length: short, long, and "overlong". In actuality, the distinction isn't purely in the phoneme length, and the underlying phonological mechanism is still disputed.
After the Estonian War of Independence, the Estonian language became the state language of the newly independent country. When the Soviet Union occupied Estonia in 1940, the status of the Estonian language changed overnight. In the second half of the 1970s, the pressure of Russification and bilingualism intensified. The Russian language was termed as ‘the language of friendship of nations’, and was taught to Estonian children as early as in kindergarten. At the same time teaching Estonian to non-Estonians was considered unnecessary. During the Perestroika era The Law on the Status of the Estonian Language was adopted in January 1989. The collapse of the Soviet Union led to the restoration of Republic of Estonia's independence. Estonian went back to being the only state language in Estonia.
Source - Wikipeadia.com