The Faculty of Liberal Arts and Sciences at Saint Petersburg State University provides its students a chance of taking Language and Thinking course first taught in Russian in the first semester and then in English in the third semester. In both cases Writing to Read interactive teaching techniques are used, which makes a comparative study of efficiency of teaching 21st Century Skills an easier task. The first semester classes are monolingual though multicultural with students from Russia as well as from CIS and former USSR republics. Students from Europe and the USF join Language and Thinking classes in the third semester, thus making them both multilingual and multicultural where EMI is the only possible means of instruction. Based on the aims of the research the analysis of students’ interviews, achievement tests and reflective works was carried out. Another method used in the research was a survey of students who attended the courses by means of course-assessing questionnaires. The study shows that while Russian and EMI can be estimated as approximately equal in ensuring the objectives of both courses, it was the course taught in English that made the students be more language aware and more self-reflective towards their mother tongue as well as English.