This paper is a progress report on how to improve teaching skills of native speaking Japanese teachers. Whenever learners acquire a word and make the semantic frame, they need the following factors: extensive examples, exceptional cases and a well organized presentation. However, low skilled teachers fail to instruct them properly because they cannot be aware of these factors. That is, they cannot use the metalanguage. We suggest they should re-experience the process of vocabulary acquisition through a riddle game activity.
