Second language acquisition is a broad topic.Therefore,I narrow it into those of cross linguistic influence.I choose copular usage for my focus of study because both Mandarin Chinese and English share this grammatical morpheme.To what extent do Copulas behave similarly between languages? This facilitates positive transfer of the first language (L1) features into the second language (L2) as Eric Kellerman (1986)observed that learners have intuitions about which language features they can transfer from their first language to the target language and which are less likely to be transferable.He further proposed that learners have a sense of what features in their L1 are in some way basic.They are more prepared to risk transferring such features than they are those they perceive to be unique to their own language.The copula is a very basic grammatical morpheme as it carries most conjugated forms.Therefore,in this dissertation,I am going to examine how Chinese Shi functions as an English copula and how it influences copular sentences in English writing.