Previous studies have shown a correlation between working memory (WM) and syntactic complexity (variously defined) in language comprehension. The present study investigates this relationship in spontaneous language production, proposing a novel metric, informed by language development and disorders, where complexity is construed in terms of those elements which are syntactically optional. This investigation uses three tests to assess memory: two WM tests (digits backwards and WM span), and one story-recall test operating over a longer timescale, and explores relationships with the production of optional elements. It examines these elements not only in English but also in German, using 20 consecutive bilinguals as participants. Results show that the amount of optional elements produced correlates significantly with the story-recall test, which indicates that, particularly at the discourse level, continuous spontaneous speech requires some sort of activated memory over a longer timescale (cf. Rapp, B., Goldrick, M., 2006. "Speaking words: contributions of cognitive neuropsychological research." "Cognitive Neuropsychology" 23 (1), 39-73). This correlation is also evident in the second language of the participants, suggesting that, at high L2 ability levels, optionality is inherent to the speaker, irrespective of language spoken. (Contains 3 tables and 1 figure.)