It has been argued that the acquisition of the English article system is delayed for most second language (L2) learners until the very final stages of learning. This paper examines the difficulties of the acquisition of this system by Persian speakers. It suggests that no single available theory can account for the causes of the learners' errors, but a combination of contrastive analysis and an analysis of these errors might be illuminating. English and Persian differ in that the former uses definite markers. It is shown that syntax has a major role in the use of the definite marker in English, whereas semantics has that role in Persian. It is predicted that if any transfer from the native language were to occur, it would most likely happen where the noun phrase carrying the article appears in subject position. An analysis of the subjects' performance on two article elicitation tasks suggests that Persian L2 learners of English have problems identifying the English definite marker when it is in subject position. (Contains 18 references.) (Author/KFT)