The 4C (Communication, Collaboration, Critical Thinking, and Creativity) skills are
significantly important for students. Teachers can support the students to develop
these skills through teaching and learning activities. This study aims to discover the
challenges teachers face in developing high school students' 4C skills in ELT classes.
The method used in this study is descriptive qualitative, used to analyze field data.
Data collection was done through interviews. The participants of this study
are three English teachers teaching in high schools. All three teachers were interview
ed. The results of this study show that teachers are observed to develop 21st century
skills. Regarding critical thinking, creativity, communication and collaboration in
identifying challenges.