This paper presents the findings from a research study conducted at one state university and one private university in Tbilisi, Georgia, in 2022-2023. The research engaged 23 university professors specialising in foreign languages and involved 203 Georgian and international students studying at various programs and language proficiency groups. The study's principal objective was to scrutinise the impact of employing L1 (native language) and L2 (second language) on acquiring a target foreign language.For Georgian students, English functioned as the target foreign language. Conversely, for international students, English served as the medium of instruction for learning Georgian as a foreign language. Beyond investigating the influences of language usage, the study sought to uncover prevalent patterns in using L1/L2 as instructional mediums. The primary objective of this research study is to examine the impact of using L1 (native language) and L2 (second language) on the acquisition of a target foreign language. Specifically, it aims to determine how L1 and L2 influence language learning outcomes and proficiency levels. The research aims to show the effectiveness of employing either L1 or L2 as an instructional medium in language education. Additionally, the study seeks to identify any patterns or variations in the use of L1 and L2 based on different language proficiency groups and language learning contexts.