The paper is divided into the following sections: In the first section a short historical survey is given which presents precursors of both Tarski's truth-condition (TTC) and Tarski's truth definition (TTD). Secondly some purported objections against Tarski's truth condition are stated and two important presuppositions of Tarski's truth condition are analyzed. Thirdly TTC is enlarged in different ways as to incorporate the preconditions explicitly. Finally in the fourth section it will be shown how the revised T-conditions solve different versions of the Liar. All of these topics are discussed in much more detail in my forthcoming book, Chapter 7.¹