The current understanding is that human-likeness of a robot leads to better human perception. However, the factors have not been thoroughly studied. We conducted a laboratory experiment to examine two questions: how verb acquisition ability affects human perceptions on human-likeness and familiarity of a humanoid robot, intention to use the robot, and enjoyment and satisfaction of the interaction, and whether human-likeness mediates the links between the effects of interaction of verb acquisition between the human perceptions. The experiment involved 48 participants, and we found that the robot that was able to acquire two Japanese verbs, ”oku (to put/to place)” and ”hanasu (to move away from),” was perceived by participants as more familiar and satisfying than the one that knew the verbs from the beginning. We also found that human-likeness mediated the links between the effect of verb acquisition ability and other perceptions toward the robot.