The current study aims to provide a feature-based account for the superficially contradictory constructions widely examined in syntax, known as the Definiteness Effect (DE) and the anti-Definiteness Effect (anti-DE). The DE is stated that the definite/ strong determiner phrases cannot serve as a notional subject. The anti-Definiteness Effect, however, is the case in which the definiteness effect vanishes, yielding the anti-Definiteness effect. In the anti-DE examples, the strong/specific/definite determiners are allowed to appear in the existential constructions (Milsark 1977, Ward and Birner 1995, McNally 1997, Abbott 1993, 1997, Keenan 2003, Hartmann 2013). In this paper, I argue that the anti-DE examples are an instance of Focus construction, which houses a bunch of syntactic as well as pragmatic features such as [focus, existence, knownness] (Bolinger 1977, Cann 2008), among others. It should be obvious that it is neither necessary nor accurate to dichotomize the determiners into Strong vs. Weak. The current proposal resolves this apparent contradiction between the DE and the anti-DE in a unified way, leading to the conclusion that there is no such thing as (anti-)DE. Furthermore, it may extend to other existential constructions such as HAVE-existentials (Quirk, et al 1976, Huddlestone and Pullum 2002, Tham 2004, Hong 2017, 2018). The ramifications of the present analysis include that there in there-existentials in English originates Spec-vP (Deal 2009) and the vP selects the Focus Projection whose most salient features include [focus, existence, knownness], among others.