This paper argues that the position of canonical (pre-verbal, non-wh DP) subjects in Brazilian Portuguese varies according to the structure in which they occur. More specifically, subjects of declarative sentences are higher than subjects in wh-sentences. It is standardly assumed that a fine-grained subject field is required, and that each position is dedicated to a different type of subject. My central claim is, however, that subjects of the same type occur in different positions depending on their structural context (hence their "slipperiness"). This proposal challenges the Subject Criterion and provides evidence for a particular approach to the satisfaction of EPP.