▁sound ▁changes : ▁r ▁corresponding ▁to ▁Common ▁Turk ic ▁z , ▁and ▁l ▁corresponding ▁to ▁Common ▁Turk ic ▁ ş . ▁ ▁Ch uv ash ▁is ▁so ▁diver gent ▁from ▁the ▁main ▁body ▁of ▁Turk ic ▁languages ▁that ▁sch ol ars ▁formerly ▁considered ▁Ch uv ash ▁not ▁to ▁be ▁properly ▁a ▁Turk ic ▁language ▁at ▁all ▁but , ▁rather , ▁a ▁Turk ified ▁Fin no - U gr ic ▁( U ral ic ▁language ). ▁However , ▁the ▁first ▁scientific ▁field work ▁mission ▁to ▁record ▁Ch uv ash , ▁by ▁August ▁A hl q v ist ▁in ▁ 1 8 5 6 , ▁established ▁its ▁correct ▁affili ation . ▁ ▁Writing ▁systems ▁ ▁Current ▁▁ 1 8 7 3 – 1 9 3 8 ▁The ▁modern ▁Ch uv ash ▁alphabet ▁was ▁de vised ▁in ▁ 1 8 7 3 ▁by ▁school ▁inspect or ▁Ivan ▁Y akov lev ich ▁Y akov lev . ▁ ▁In ▁ 1 9 3 8 , ▁the ▁alphabet ▁under w ent ▁significant ▁modification ▁which ▁brought ▁it ▁to ▁its ▁current ▁form . ▁ ▁Pre vious ▁systems ▁The ▁most ▁ancient ▁writing ▁system , ▁known ▁as ▁the ▁Old ▁Turk ic ▁alphabet , ▁disappeared ▁after ▁the ▁Vol ga ▁Bulg ars ▁converted ▁to ▁Islam . ▁Later , ▁the ▁Arab ic ▁script ▁was ▁adopted . ▁After ▁the ▁Mong ol ▁invasion , ▁writing ▁de grad ed . ▁After ▁Peter ▁the ▁Great ' s ▁re forms ▁Ch uv ash ▁el ites ▁disappeared , ▁black sm ith s ▁and ▁some ▁other ▁craft s ▁were ▁prohib ited ▁for ▁non