Two sets of production tests were conducted in January and February in 2012, both in Tokyo and in Mannheim (Germany) to capture differences of utterances which subjects produced with or without the presence of another person, who sat at 45 deg. left in front of them, remained silent, but pretended to be ready to talk with them. The subjects were requested to describe or comment on objects appearing on the computer display at an interval of 10 sec. Our working hypothesis is that intersubjective expressions such as end-particles in Japanese (JEPs) and modal particles in German (GMPs) would be more freuently observed with the presence of a potential interlocutor. The result was that although the influence was confirmed, GMPs were rarely used even in her presence, while JEPs were frequently used even without her presence. This sugguests that there is a crucial difference in terms of interlocutor's commitment.