a - n - na , ▁where ▁the ▁neg ation ▁marker ▁- n ▁is ▁copied ▁several ▁times . ▁As ▁for ▁t ense , ▁the ▁non p ast ▁is ▁over t ly ▁marked ▁by ▁- me ʔ ▁or ▁- wa . ▁Both ▁suffix es ▁have ▁their ▁origin ▁in ▁gram mat ical ized ▁lex ical ▁ver bs ▁(" do " ▁and ▁" be / exist " ▁respectively ). ▁They ▁occup y ▁different ▁sl ots ▁in ▁the ▁ver bal ▁suffix ▁template . ▁The ▁past ▁is ▁marked ▁by ▁the ▁suffix ▁- a , ▁which ▁is ▁often ▁el ided ▁to ▁avoid ▁hi atus ▁in ▁underlying ▁v owel ▁sequences . ▁The ▁perfect ▁t ense ▁is ▁built ▁by ▁the ▁addition ▁of ▁the ▁suffix es ▁- ma ▁or ▁- u ks ▁to ▁the ▁past ▁morph eme , ▁and ▁the ▁past ▁perfect ▁t ense ▁is ▁built ▁by ▁further ▁addition ▁of ▁the ▁suffix ▁- sa ▁to ▁this ▁suffix ▁string . ▁As ▁for ▁m ood , ▁the ▁imper ative ▁is ▁also ▁c oded ▁by ▁the ▁suffix ▁- a , ▁e . g . ▁ab - a ▁" Come !" ▁In ▁trans itive ▁ver bs ▁with ▁a ▁third ▁person ▁patient , ▁the ▁over t ▁suffix ▁is ▁- u , ▁and ▁the ▁imper ative ▁suffix ▁is ▁not ▁over t ly ▁real ised . ▁The ▁sub j unct ive ▁m ood ▁has ▁no ▁dedicated ▁marker , ▁it ▁is ▁marked ▁precisely ▁by ▁the ▁absence ▁of ▁anything ▁but ▁the ▁agreement ▁morph ology , ▁e . g . ▁ci ya ▁h ops - u - m ? ▁" Sh all