In the present study, I have analysed changes in writing and genre in grade 9 during the period 1992–2013. My hypothesis requires more informal language and thus poorer adjustment to the right genre. I use a language theory (Teleman 1985) and theories that highlight the chang-es in school and rest of the community. The study material is taken from the years 1992, 2003 and 2013, and consists of 64 essays. The quantitative analysis of student texts reported in study 1 is based on word variation (OVIX), nominal quota value (NQ), percentage of long words, the average graphic sentence length, noun phrases longer than one word and the number of words in student texts. Sub-study 2 is a qualitative genre analysis of six selected essays, in which two from each year were analysed. The selected essays are the closest to and farthest from the prose style genre normally used in society. The analysis showed the following results. OVIX, nominal quota and noun phrases show a negative change in students’ discursive language over time. The differences between the stu-dents declined between 1992 and 2003, but increased during the period 2003–2013. Long words, the average sentence length and the number of words increased between 1992 and 2013. Study 2 showed a result that did not differ much over time. Questions in the texts increased in 2013. The students who wrote mainly in genre-adapted style are also capable of writing about the stances they take on various topics.