. ▁ ▁Single ▁ ▁is ▁also ▁restricted ▁to ▁quantity ▁ 1 , ▁but ▁altern ates ▁with ▁. ▁ ▁Vo iced ▁stops ▁and ▁aff ric ates ▁only ▁occur ▁in ▁quantity ▁ 3 , ▁except ▁for ▁ ▁which ▁can ▁also ▁occur ▁in ▁quantity ▁ 2 . ▁▁ ▁occurs ▁in ▁quantity ▁ 2 ▁and ▁ 3 , ▁but ▁not ▁in ▁quantity ▁ 1 . ▁ ▁When ▁a ▁con son ant ▁can ▁occur ▁in ▁all ▁three ▁quantities , ▁quantity ▁ 3 ▁is ▁term ed ▁" over long ". ▁ ▁Ph on ological ▁processes ▁ ▁Um la ut ▁ ▁Um la ut ▁is ▁a ▁process ▁where by ▁a ▁di ph th ong ▁in ▁a ▁str essed ▁sy ll able ▁changes ▁depending ▁on ▁the ▁v owel ▁in ▁the ▁next ▁sy ll able . ▁ ▁The ▁first ▁type ▁of ▁um la ut , ▁causes ▁an ▁altern ation ▁between ▁ ▁and ▁ ▁in ▁words ▁whose ▁st ems ▁end ▁with ▁un str essed ▁. ▁For ▁such ▁words , ▁these ▁two ▁di ph th ongs ▁can ▁be ▁considered ▁variants ▁of ▁each ▁other , ▁while ▁in ▁words ▁whose ▁st ems ▁end ▁with ▁another ▁v owel , ▁these ▁v ow els ▁remain ▁distinct . ▁The ▁following ▁table ▁shows ▁the ▁different ▁patterns ▁that ▁occur ▁with ▁different ▁following ▁v ow els : ▁ ▁The ▁second ▁type ▁of ▁um la ut , ▁called ▁" di ph th ong ▁simpl ification " ▁or ▁" mon oph th ong ization ", ▁is ▁similar ▁to ▁its ▁Northern ▁Sam i ▁counter part , ▁but ▁works ▁differently . ▁The ▁di ph th ongs