In this chapter, we ponder why highly advanced tutored learners perform differently than their naturalistic L2 counterparts at the same level of proficiency in certain, predictable contexts. The Competing Systems Hypothesis (CSH) (Rothman 2008) attempts to explain some of these differences, appealing to the deterministic role played by pedagogically-designed metalinguistic knowledge that only tutored learners have. We will review one study done to test the CSH, Rothman (2008), which compares and contrasts near-native tutored and naturalistic L2 learners of Spanish in the domains of grammatical (viewpoint) aspect. Using Rothman’s (2008) findings as an example, we will outline how one can reduce the gap between linguistic descriptive grammars and pedagogical grammars in an accessible and usable way for language teaching.