Armenian is an Indo-European language. At present, Armenian is spoken in the Republic of Armenia and the Republic of Artsakh (Nagorno-Karabakh Republic / Mountainous Gharabagh), as well as in diaspora countries
such as Russia, USA, France, Italy, Georgia, Syria, Lebanon, Iran, Argentina, Turkey, and Ukraine. Historically, Armenian was spoken on a vast territory that included the Armenian Highlands (the Armenian plateau) and some adjacent
areas of it. Historical Armenia (known as Hayk‘ and Hayastan, based on hay ‘Armenian’) was centred around Mount Ararat (Masis), Lake Van and the Araxes (Erasx) Valley.
The Armenian language is known to us from the fifth century CE onwards thanks to an unbroken literary tradition comprising three periods: Classical (5th to 11th centuries), Middle (12th to 16th), and Modern
(17th to present). Furthermore, one usually distinguishes around fifty or sixty modern Armenian dialects, a number of which have died out, partly as a consequence of the Armenian Genocide. Classical Armenian is named Grabar, literally: ‘written (language), book (language) / Schriftsprache’. The fifth century is regarded as the Golden Age of Armenian literature. The Armenian alphabet was invented by Mesrop Maštocʻ in
405/406 CE and consisted of 36 original letters.
Armenian plays an important role for the reconstruction of the Indo-European proto-language, despite it having undergone a number of significant changes, particularly in the verbal system. In contrast to Modern Armenian, in which
morphological marking is closer to an agglutinative type, Classical Armenian is an inflectional language with noticeable Indo-European characteristics. Morphological categories are mostly expressed through suffixation, although some
involve prefixes (e.g. 3sg.aor. e-) or internal vowel changes (e.g. the stem variation between -in, -un and -an, reflecting the Indo-European ablaut *-en-, *-on- and *-n̥, respectively).
There are seven cases: nominative, accusative, genitive, dative, ablative, instrumental, locative, and two groups of declension classes: exterior/vocalic (or invariable) and interior/consonantal (or variable). The PIE dual and
grammatical gender have been lost but their traces are still observable in stem vowels.
The verbal system is centred on the opposition between a present and an aorist stem. The indicative present, indicative imperfect, subjunctive present and prohibitive (imperative present) are formed from the present stem, while the
indicative aorist, subjunctive aorist, imperative aorist and cohortative (imperative future) are based on the aorist stem.
In certain respects Classical Armenian retains archaic Indo-European features and in many others it displays innovations. An interesting issue that combines archaism and innovation is the PIE archaic neuter heteroclitic *-r/n- declension, of which we only find some residual evidence in Armenian, such as hur ‘fire’ vs. obl. *hun- (in hn-oc‘ ‘oven, furnace’), and which developed new paradigms in such words as nom. cunr vs. obl. c(u)ng- ‘knee’ and nom. asr vs. gen. asu ‘wool, fleece’.