Linda Janita Thine Pengarang GRACIA M. N. OTTA Dosen Pembimbing 1 SELFIANA P MBADI Dosen Pembimbing 2 Gracia M. N. Otta Penguji 1 Tans Feliks Ketua Penguji SELFIANA P MBADI Penguji 2

The aims of this research were to find out the the students' ability and curiosity of the flipped classroom application in learning conditional sentences. The English Club members of SMA Kristen Pandhega Jaya were chosen as the subject of this research. The research focused on applying the flipped classroom in learning conditional sentences. The method used in this study was descriptive qualitative methods. The techniques of data collection were pre and post-test and interviews. The results show that the students' scores increased significantly from pre-test to post-test In pre-test, only 5% student that reached the Minimum Mastery Criteria, while in post-test it changed to 90%. The students' mean score also improved from 31.5 to 82.0 the flipped classroom model can build students' curiosity in learning conditional sentences. By making them more active through pre-learning activity, by encouraging them to overcaming their diffuclties, by asking them to find out solutions to their problems, by interactive more with teacher, by having discussion with their peers, and by developing their interest.