Öz
In recent years, some studies have been conducted on the transfer of the first and second language to the third language in order to investigate cross-linguistic influence. This study aims to analyse the causes of cross-linguistic effects by examining the transfer of L1 and L2 during the L3 acquisition. A total of 7 individuals who learn Italian as L3 participated in the study. Individuals' attitudes in the classroom, writing examples and classroom conversations were examined, their opinions were taken and the effects of L1 and L2 on L3 were examined. The study results show that the more learned languages are typologically close, the easier it is to learn. It also demonstrates that there is no exact evidence in transfer between languages.