Constitution. In 2010, Uttarakhand became the first state in India to make Sanskrit its second official language. In 2019, Himachal Pradesh made Sanskrit its second official language, becoming the second state in India to do so. Phonology Sanskrit shares many Proto-Indo-European phonological features, although it features a larger inventory of distinct phonemes. The consonantal system is the same, though it systematically enlarged the inventory of distinct sounds. For example, Sanskrit added a voiceless aspirated "tʰ", to the voiceless "t", voiced "d" and voiced aspirated "dʰ" found in PIE languages. The most significant and distinctive phonological development in Sanskrit is vowel merger. The short *e, *o and *a, all merge as a (अ) in Sanskrit, while long *ē, *ō and *ā, all merge as long ā (आ). Compare Sanskrit nāman to Latin nōmen. These mergers occurred very early and significantly impacted Sanskrit's morphological system. Some phonological developments in it mirror those in other PIE languages. For example, the labiovelars merged with the plain velars as in other satem languages. The secondary palatalization of the resulting segments is more thorough and systematic within Sanskrit. A series of retroflex dental stops were innovated in Sanskrit to more thoroughly articulate sounds for clarity. For example, unlike the loss of the morphological clarity from vowel contraction that is found in early Greek and related southeast European languages, Sanskrit deployed *y, *w, and *s intervocalically to provide morphological clarity. Vowels The cardinal vowels (svaras) i (इ), u (उ), a (अ) distinguish length in Sanskrit. The short a (अ) in Sanskrit is a closer vowel than ā, equivalent to schwa. The mid vowels ē (ए) and ō (ओ) in Sanskrit are monophthongizations of the Indo-Iranian diphthongs *ai and *au. The Old Iranian language preserved *ai and *au. The Sanskrit vowels are inherently long, though often transcribed e and o without the diacritic. The vocalic liquid r̥ in Sanskrit is a merger of PIE *r̥ and *l̥. The long r̥ is an innovation and it is used in a few analogically generated morphological categories. According to Masica, Sanskrit has four traditional semivowels, with which were classed, "for morphophonemic reasons, the liquids: y, r, l, and v; that is, as y and v were the non-syllabics corresponding to i, u, so were r, l in relation to r̥ and l̥". The northwestern, the central and the eastern Sanskrit dialects have had a historic confusion between "r" and "l". The