- Chomsky's theory of Universal Grammar (UG) proposes that humans are born with innate, universal principles of grammar that are common across all human languages.
- UG consists of principles and parameters - principles are universal across languages while parameters vary and are set based on a child's language input.
- There are debates around whether and how UG is accessible for second language acquisition. The direct access view is that UG operates the same in L1 and L2 acquisition. The indirect access view is that L2 learners can only access UG through their L1. The no access view is that L2 learners have no access to UG.