G-TAG is a Tree Adjoining Grammar (TAG) based formalism which was specifically designed for the task of text generation. Contrary to TAG, the derivation structure becomes primary, as pivot between the conceptual representation and the surface form. This is a shared feature with the encoding of TAG into Abstract Categorial Grammars. This paper propose to study G-TAG from an ACG perspective. We rely on the reversibility property of ACG that makes both parsing and generation fall within a common morphism inversion process. Doing so, we show how to overcome some limitations of G-TAG regarding predicative adjunction and how to propose alternative approaches to some phenomena.