摘要：Abstract This paper discusses the different views on the availability of UG principles in language acquisition of adult second language learners, and summarizes some of the evidence for or against each position. One important issue in current language acquisition research is whether the acquisition of a second language is fundamentally different from that of the first language. Researchers approaching second language acquisition (SLA) from the linguistic perspective often relate this issue to the availability of Universal Grammar to second language acquisition. Universal Grammar (UG) refers to a grammar which is genetically endowed to all human beings and which all languages have in common.
