This paper presents preliminary results from a socially interactive humanoid robot assisted Sign Language (SL) tutoring system for children with communication impairments, by means of imitation based interaction games. In this study, the 5 fingered robot platform Robovie R3 will be able to express a set of chosen words in SL using hand movements, body and face gestures. The study consists of an introductory phase, where participants are passive observers of the robot, an imitation based learning phase, where participants are motivated to imitate the signs demonstrated by the robot, and the game phase where the signs taught in the previous phases are tested within an interaction game. The aim of this interactive game phase is the reinforcement of the signs taught visually, semantically and kinematically in the previous phases in a motivating and engaging way, as well as testing the learning performance of the participants. The game also aims to improve children’s imitation and turn-taking skills and to teach the words semantically. Current paper presents results from the preliminary study with adults (without hearing disabilities).We use the humanoid robot as an assistive educational medium in this game, to evaluate the participant’s sign languagelearning ability from a robot, and comparison of different robot platforms within this setup.