There are about 200 bilingual secondary schools in Hungary (10-12% in public education) where one can reach level C1 during 4-6 years of learning a foreign language in 8-10 lessons per week and having 3-5 subjects taught in the target language. Since the highest foreign language level one can reach at the final examination of the Hungarian public education is B2, the state issues a C1 certificate only if the students take their examinations in the target language in at least two subjects. Let alone, requirements of the examination in a target language are equal to those in Hungarian language - the exam is unified. According to several research projects carried out between 2006 and 2009, in 70% of the secondary schools, teachers can decide whether to include the mother tongue in teaching the subjects in the target language. Their decision is filled with aspects of language pedagogy that is, e.g. the linguistic solutions of the given content widely differ in the two languages therefore there is much to be accounted for. The results of students taking exams in a foreign language are not inferior to the national examination results taken in Hungarian. Simultaneously, it can be ascertained that: 1 Students have confidence in the success of future final examination according to the role the two languages of instruction played in their teaching; the language component of their subject knowledge. 2 The aim of using target language at the actual final examination is mainly for proving foreign language competence, while earlier the subject content was in the focus of teaching. 3 With the simple (word by word) translation of the examination tasks, the final examination practically requires a C2 level of language knowledge. Questions may refer to the characteristics of changing language and to how these changes are related to the language of the examination and to the subject knowledge.