This entry brings together the topics of humor and second language acquisition, focusing mainly on issues concerning adult and adolescent language learners, as the situation of child language learners, who are still developing both humor and linguistic competence, is too complex to address here. The term second language acquisition can be understood as encompassing all additional language learning, rather than simply a second language. It includes language learning that is undertaken in a classroom, as well as that which takes place naturalistically, without instruction. Both the use and understanding of humor represent a formidable linguistic and cultural challenge to language learners, yet it is crucial that they meet this challenge, given the important role humor plays in human interaction. This entry begins with a discussion ...