The aim of this thesis is to characterise the shifting relationship between public and private education in nineteenth-century Sweden. It does so by a study of modern language teaching in Stockholm 1800–1880. Whereas modern languages had long been taught by private language masters, German, French and English were only officially recognised as subjects of public grammar schools in 1807. The study shows that, unlike the impression given by earlier studies, the introduction of public teaching of modern languages did not bring an end to private language instruction. The study further demonstrates that although private language teaching continued to thrive alongside the expanding public language education, the relationship between the two types of education changed over time. Until the 1840s, both private and public education operated as competitors in a local educational market, adjusting their language teaching to local demand and mutual competition. A crucial condition for this competition was the fact that state curriculums still had a relatively limited impact on the actual teaching of public schools. In the later part of the century, the language teaching within public schools became more influenced by the idea of formal education, leading to an increased focus on grammar. Simultaneously, the role of private language instruction evolved into complementing public teaching, primarily by providing the practical proficiency neglected in public schools. While the study questions the importance and effects of central reforms, especially in the earlier decades of the 19th century, it points to other significant factors that influenced the local education market. In particular, the gradual centralisation and systematisation of public schools diminished their ability to cater for local demand. But the growing importance of formal credentials meant that public schools had less need to compete for students. Students were no longer necessarily attracted by the practical usefulness of schooling, creating both the possibility of the specific form of language teaching that developed within public schools, as well as the need of supplementary private instruction.