As a result of an increased number of multilingual children in Sweden, the need for knowledge and understanding of multilingual language development also increases. An accurate use of past tense plays a crucial role in effective communication, not least when it comes to temporal reference and storytelling. The purpose of this paper is to investigate how multilingual Turkish-Swedish speaking children, aged 4 and 6, use past tense in Swedish narratives and whether any connections can be made to the Turkish past tense system. The study is based on 126 narratives told by 53 different children at the age of 4 and 6 years. The study was carried out both cross-sectionally and longitudinally, as 10 of the 4 year olds redid the same test 2 years later; when 6 years old. The narratives were elicited using the assessment material MAIN (Multilingual Assessment Instrument for Narratives, Gagarina et al., 2019). The findings from the cross-sectional study show that the 6-year-olds show a stronger preference for simple past tense and also conjugate the verbs with higher accuracy than the 4-year-olds. The 6-year-olds show a more developed ability to form past tense depending on whether the verb is weak or strong, while the 4-year-olds make more use of overgeneralization of the regular weak conjugation patterns. Possible connections with the Turkish tense system can be identified in terms of use of \textit{light verb constructions}, double marking with Turkish past tense endings, as well as overuse of nonfinite past participle endings. The results from the longitudinal study to some extent confirm the cross-sectional generalisations, but also shed light on the individual variation among children and thus reconnect to and stress the importance of knowledge and understanding of multilingual language development.