This paper provides a research synthesis of intelligent personal assistants (IPAs) -- that is, cloud-based virtual assistants such as Alexa, Google Assistant, and Siri -- for second language (L2) learning. The article also offers a theoretical justification for the use of IPAs in language learning and outlines the affordances and constraints of the technology. Finally, the article proposes directions for future research on the topic of IPAs based on the aforementioned review of L2 literature. While research indicates that IPAs increase opportunities for meaningful communication in the target language, enhance speaking ability, and provide indirect pronunciation feedback, they also present some challenges for L2 learners -- namely, IPAs struggle to reliably understand L2 speech, which may limit the usability of virtual assistants among heavily accented learners.