This article addresses the debate on the causes of variability in production of second language functional morphology. It reports a study on article production by first language (L1) Serbian/second language (L2) English learners and compares their behaviour to that of a Turkish learner of English, reported in Goad and White (2004). In particular, it focuses on the tendency of these learners to omit articles more in adjectivally pre-modified (Art + Adj + N) than in non-modified contexts (Art + N). The asymmetry is found in both spoken and written production. The article argues that the pattern of results is not consistent with models assuming target-like syntax: the Missing Surface Inflection Hypothesis cannot predict the asymmetry at all, and the Prosodic Transfer Hypothesis cannot extend its explanatory power to spoken production of L1 Serbian/L2 English learners, or to written production in general. An alternative account, with broader empirical coverage, is proposed, on which L2 learners whose L1s do not grammaticalize definiteness misanalyse English articles as nominal modifiers, and treat them in production as such. The model goes beyond the representational deficit vs. processing constraints debate, in that it suggests that variability is caused by processing limitations, but precisely because the production of misanalysed elements cannot be (directly) syntactically motivated, and has to rely on general cognition instead. (Contains 4 tables, 5 figures and 15 footnotes.)