There has been a growing concern about the use of English in informal conversations of the Latvian youth. The present research aims to gain an insight into the use of English in informal conversations of the Latvian youth occurring primarily in Latvian and to arrive at conclusions regarding the potential reasoning behind it. Codeswitching was chosen for further analysis as one of the most common multilingual practices among the youth. In order to determine the use of English in informal conversations of Latvian youth, a sociolinguistic research was carried out, applying methods of field linguistics developed specifically for researching code-switching. An original corpus of transcribed spontaneous speech recordings of conversations between adolescents of three age groups (eighth-grade students, eleventh-grade students and university students) was developed. The results showed code-switching as a prevalent feature of Latvian youth communication, and a correlation between English proficiency and code-switching use was established.