Recent important sociocultural changes, such as the expansion of mass media, have profoundly changed language interaction, especially between teenagers. This project aims to investigate how the Spanish teen language has changed over the past two decades. Concretely, the project has four main objectives. First, it will investigate the rate and nature of language change by monitoring six characteristics operating at the lexical and syntactic level, namely taboo words, pragmatic markers, lexical borrowings, syntactic inclusions, syntactic simplifications and syntactic borrowings, at two different points in time, i.e. at the onset of the 21st century and at the beginning of the third decade. This comparison will reveal whether there is a difference in rate between lexical and syntactic change. Second, from a sociolinguistic perspective, the project analyzes if gender, social class or the network has an impact on these language changes. In a third stage, it investigates whether teenagers are rightly defined in the literature as leaders of language change. Finally, it examines the phenomenon of age-grading and the validity of the apparent-time method. In order to accomplish these goals, the project combines corpus analyses with experimental data.