The markedness theory was introduced into language transfer researches in 1970s。 These researches found out that in language learning, the one marked is more difficult to acquire than the one unmarked and the degree of markedness is in direct proportion to the learning difficulty。 The Universal Grammar of Chomsky holds the view that people are born with shared basic language rules, which are the core grammars of people。 What people need to learn are that periphery grammars which could distinguish different languages。 Under normal circumstances, the core grammars aren’t marked, while the periphery grammars are marked。 With this characteristic, Eckman put forward the Markedness Differential Hypothesis which holds the view that the part of target language whose markedness is stronger than mother tongue’s is the most difficult part to acquire; but the part of target language whose markedness is weaker than mother tongue’s is easy to acquire。 Ellis (1985) summarized the relation of language markedness and mother tongue transfer as follows: