Abstract:( Ni) yisi( shi) + X(literally "(you) mean (be) + X") occurring at different sequential positions may execute various social actions. This research adopts conversation analysis as its research methodology and probes into "( ni) yisi( shi) + X" as the third turn in the questioning/answering sequence. Data analyses prove that "( ni) yisi( shi) + X" at this sequential position displays the questioner's difficulty in understanding the answer, thus the questioner initiates a repair with "( ni) yisi( shi) + X" to provide the answerer with an opportunity to confirm, disconfirm the questioner's candidate understanding or even to further provide more relevant details. Our conclusion is that "( ni) yisi( shi) + X" shows the questioner's local analysis of the answer and displays the questioner's difficulty in understanding. The overall sequence organization manifests the questioner and answerer's mutual orientation to the moment-by-moment unfolding of a conversation and their mutual efforts to achieve intersubjectivity in talk-in-interaction.