"Most human beings grow up speaking more than one language; a lot of us also acquire an additional language or languages other than our mother tongue. This Element in the Second Language Acquisition series investigates the human capacity to learn additional languages later in life and introduces the seminal processes involved in this acquisition. The authors discuss how to analyze learner data and what the findings tell us about language learning; critically assessing a leading theory of how adults learn a second language: Generative SLA. This theory describes both universal innate knowledge and individual experiences as crucial for language acquisition. This Element makes the relevant connections between first and second language acquisition and explores whether they are fundamentally similar processes. Slabakova et al. provide fascinating pedagogical questions that encourage students and teachers to reflect upon the experiences of second language learners"--.