友(とも)達(だち) tomodachiに ni２０ 20年(ねん) nenも mo会(あ)っ()て()な()い() attenai。 I haven't seen my friend in twenty years. Literal Friend [target-に] 20 years [emphasis-も] not-met. も after a quantity adds emphasis — 'as many as 20 years.' 会ってない is the contracted form of 会っていない, dropping the い from ~ていない. This contraction is standard in casual speech and mirrors the ~てる contraction of ~ている. friendshiptime expressions~てる (contraction of ~ている)
友(とも)達(だち) tomodachiに ni２０ 20年(ねん) nenも mo会(あ)っ()て()な()い() attenai。 I haven't seen my friend in twenty years. Literal Friend [target-に] 20 years [emphasis-も] not-met. も after a quantity adds emphasis — 'as many as 20 years.' 会ってない is the contracted form of 会っていない, dropping the い from ~ていない. This contraction is standard in casual speech and mirrors the ~てる contraction of ~ている. friendshiptime expressions~てる (contraction of ~ている)