▁the ▁one ▁given ▁example ▁used ▁in ▁this ▁journal ▁being ▁i bl í ̃ x do ▁(' black bird '), ▁is ▁mentioned ▁as ▁being ▁an ▁error ▁for ▁the ▁spir ant ▁+ ▁stop ▁combination ▁h d . ▁But ▁the ▁spir ant ▁+ ▁stop ▁combination ▁x d ▁has ▁also ▁been ▁found ▁in ▁the ▁words ▁ch é x d ó ▁(' buff alo ▁b ull '), ▁ná x da ▁(' s our '), ▁and ▁ná x d age ▁(' k ick '). ▁With ▁this ▁data ▁we ▁can ▁see ▁that ▁the ▁con son ant ▁cluster ▁x d ▁is ▁a ▁possible ▁combination ▁and ▁can ▁show ▁up ▁in ▁word ▁med ial ▁position . ▁ ▁V ow els ▁Ch iw ere ▁has ▁five ▁or al ▁v owel ▁ph on emes , ▁, ▁and ▁three ▁nas al ▁v owel ▁ph on emes , ▁. ▁V owel ▁length ▁is ▁distinct ive ▁as ▁well . ▁ ▁Gram mar ▁Ch iw ere ▁grammar ▁is ▁ag gl ut in ative ; ▁its ▁ver bal ▁complex ▁is ▁central ▁to ▁the ▁structure ▁of ▁the ▁language . ▁ ▁Ver bs ▁are ▁formed ▁by ▁addition ▁various ▁aff ix es ▁to ▁a ▁verb ▁stem , ▁each ▁of ▁which ▁corresponds ▁to ▁a ▁part ▁of ▁speech , ▁such ▁as ▁a ▁pre position , ▁pron oun , ▁case ▁marker ▁and ▁so ▁forth . ▁ ▁Con cept s ▁such ▁as ▁possession , ▁ref lex ivity ▁and ▁gram mat ical ▁number , ▁as ▁well ▁subject - object ▁relation ▁and ▁case ▁( including ▁nine ▁instrument al ▁prefix es ) ▁are ▁also ▁expressed ▁via ▁aff ix ing .