The project is evaluating the "First Language Teaching" (ESU) program at Berlin schools on behalf of the Berlin Senate. Since 2018, first (heritage) language lessons in Turkish and Arabic have been offered at Berlin schools and expanded to other languages, incorporating the specially developed curriculum framework since the school year 2022/23. A systematic analysis of conditions, processes and effects of the ESU program in Berlin will be carried out with a focus on Turkish and Arabic as the most frequently offered languages. During the evaluation, the current situation regarding the implementation of first language teaching at schools will be examined by means of surveys, concrete suggestions for improvement of the ESU program will be developed, and language skills and their development in selected domains in both languages of the students attending the ESU will be investigated on the basis of a selected sample.