This work presents the preliminary results of an ongoing project which aims to use humanoid robots as sign language tutors. The study mainly focuses on children who have some problems when they are communicating with other individuals such as hearing-impaired or autistic children. In this paper, an interactive game, which is based on sign language, between a humanoid robot and a human participant is introduced. The game consists of an imitation based learning phase where the signs are taught in the first step and they are tested in the second step within the frame of an interaction game. The goal of the interactive game is to reinforce the semantic meaning of the signs in a motivating and engaging way, as well as to test the learning performance of the participants. We aim to design a comfortable learning environment by using the humanoid robot as an educational medium. The game also improves the participants' imitation and turn-taking skills and teaches the semantic meanings of the signs.