- r - tar ▁( PER F - PL - cut ) ▁→ ▁a : rac ar ▁' he ▁has ▁cut ▁them ' ▁a : ra - tar ▁( PER F - cut ) ▁→ ▁a : rat ar ▁' he ▁has ▁cut ▁it ' ▁▁ ▁changes ▁to ▁ ▁whenever ▁it ▁follows ▁a ▁con son antal ▁segment ▁which ▁is ▁not ▁ ▁or ▁: ▁▁ ▁i - s - wa ▁( I MP ER - you - go ) ▁→ ▁is k wa ▁' go !' ▁ ▁i - t - wa ▁( I MP ER - I - go ) ▁→ ▁ ick wa ▁' let ▁me ▁go !' ▁▁ ▁changes ▁to ▁ ▁before ▁ ▁or ▁. ▁The ▁most ▁numerous ▁examples ▁involve ▁the ▁collect ive - pl ural ▁prefix ▁r - ▁before ▁a ▁morph eme ▁beginning ▁with ▁: ▁ ▁ti - r - k ita - re : s ʔ i ▁( IND IC - CO LL - top - lie . IN AN ) ▁→ ▁t ih kit are : s ʔ i ▁' they ▁are ▁lying ▁on ▁top ' ▁▁ ▁with ▁a ▁following ▁ ▁or ▁ ▁to ▁give ▁: ▁ ▁ke ʔ e - t - ri ka : s - ti : k wi ▁( F UT - I - head - hit ) ▁→ ▁ke ʔ e ci ka : st i : k wi ▁' I ▁will ▁hit ▁him ▁on ▁the ▁head ' ▁▁ ▁changes ▁to ▁ ▁before ▁ ▁or ▁any ▁non - v owel : ▁ ▁ta