While many current models of verbal working memory acknowledge interactions with verbal long-term memory, the nature of these interactions remains a matter of debate. I will present a series of behavioral and neuroimaging studies showing that (1) subtle aspects of language knowledge such as syntactic positional knowledge can influence verbal working memory, (2) the neural substrates of verbal working memory cannot be defined independently of the linguistic nature of the stimuli to-be-maintained, (3) recruitment of deep semantic knowlegde may not characterize all working memory situations. These resuls support hybrid linguistic models of verbal working memory considering that verbal working memory is grounded in the language system but cannot be reduced to the language system.