In the research of focus on intonation languages, it is generally assumed that the stress not only signals the focus but also contributes to the different truth condition in sentences containing focus particle only. This phenomenon is known as ¡¥association with focus¡¦ (Jackendoff, 1972; Rooth, 1985, 1992, among others). However, this phenomenon has not been comprehensively studied in tonal languages such as Chinese. To further investigate whether the stress signals the focus in triadic sentences with zhi ¡¥only¡¦ and whether there is a preferred default focus interpretation, the study probes into the issue with respect to younger participants, i.e., teenagers in junior high schools. The study contains triadic sentences such as dative construction, double object construction and ba construction. Participants were asked to choose the focus which zhi ¡¥only¡¦ is associated with in a multiple choice questionnaire after the stories and test sentences were shown by a powerpoint file in the computer. There were three experiments in this study. In Experiment 1, 116 participants in the regular classes judged a contrastive stress awareness task and a modified Truth Value Judgment (TVJ) Task. Experiment 2 (TVJ task only) followed Experiment 1 except for using unfamiliar Cartoon figures. Experiment 3 (the contrastive stress awareness task and the TVJ task) reduplicated Experiment 2 in English. The participants in Experiment 2 and 3 were the same 30 participants in the gifted class. The results, first, further confirmed that even though Chinese teenagers were aware of the contrastive stress, they did not use it for disambiguating sentences with zhi ¡¥only¡¦ in both Chinese and English. Second, the participants tended not to choose the default wide VP focus but narrow focus. However, contrary to the default narrow DO focus that Chinese adult speakers preferred, the teenager participants favored the narrow focus which usually falls on the neutral stress (sentence-final) position. The phenomenon is even more salient in ba construction. Third, in English, contrastive stress was not used for disambiguation although they were aware of the stress. The interpretation of English focus particle only was similar to that of Chinese, so it was ascribed to L1 transfer.