This study investigates second language acquisition of English noun phrases in discourse, examining the effect of discourse markedness and structural markedness on the development of noun phrase use. English L2 noun phrase forms are examined within three universal discourse contexts: current, known, and new reference to topics. The targeted noun phrases forms include ø anaphora, pronouns and nouns with markers of definiteness and indefiniteness, including left dislocation and existential phrases. Based on expectedness within discourse, the least marked discourse context is reference to a current topic, and the most marked context is the introduction of a new referent as topic. Based on formal complexity, ø anaphora is the least marked structural form, and left-dislocated and existential noun phrases are the most marked. Free production and elicited imitation recall tasks, involving picture sequences that manipulated the three discourse contexts, were used to test Japanese learners' acquisition of noun phrase forms. They were evaluated by comparison with NS production. The results support predictions that L2 learners distinguish between discourse contexts, acquiring more targetlike forms in the least marked context first, and that they acquire the least marked structural forms earlier than the more marked ones.