摘要:This article discusses the early phases of acquisition of noun compounds in two typologically different languages – Estonian and Russian. Longitudinal data on three Russian and two Estonian typically-developing monolingual children and their caregivers was analysed and compared in relation to first emergence, the development of different compound types, productivity, frequency, simplicity and transparency of compounds, and also to the impact of morphological wealth in the input on the output. Although the frequency of compounds is somewhat different in the two languages being observed, the first compounds emerge in the speech of Estonian and Russian children almost at the same age and quite early, at the end of the second year of life. In both Estonian and Russian, children first acquire productive pat- terns in both languages, Estonian and Russian, respectively. Factors such as simplicity and frequency are intertwined in the acquisition process. Simple structures occur at the same time as frequent ones but it cannot just be assumed that simplicity is a stronger factor influencing the choice of first noun compounds than frequency. Frequency effects are not straightforward: there are differences in the individual usage of compounds by the caregivers, and the frequency of compounds in child-directed speech does not always seem to be reflected in the speech of the children. DOI: http://dx.doi.org/10.5128/ERYa9.02