This case study followed the process of first language acquisition of a child learning the Croatian language. A Croatian girl named Franka was recorded in her home, by her parents, several times per month, from the age of two until the age of three years old. The goal of the study was to collect recordings of the child’s spontaneous speech in order to examine more closely the development of interrogative forms in children learning Croatian, as compared to children learning English as their first language. The paper first provides a comparison between the ways interrogative forms are constructed in English and Croatian. It gives an overview of previous findings on question acquisition, focusing more narrowly on the acquisition of wh-questions. What was gathered from the acquired data is then compared to a study of communicative functions in typically developing Croatian children, as well as to general information on question acquisition found in readers and studies on language development, which were mainly grounded on data collected from children learning English. Finally, it is shown that the results from the case study point to similarities as well as some significant differences in the processes of question acquisition between children acquiring Croatian in comparison to children acquiring English as their first language.