This test on the phrase tte yuu ka (TYK) employed as a “repair preface” in the context of substituting one formulation with another, displays that the use of TYK in the operation of substitution self-repair teaches the receiver to grasp the repair solution as a better fit option for whatever aim the speaker may be chasing. It also shows how this trait of TYK is employed as a resource to attain situated interactional work in talk-in-interaction in both everyday and institutional environs. Data are Japanese with English translation.