This paper studies in depth the Greek adverb τάχα and its grammaticalization. The author tracks down its etymological origin from Ancient to Modern Greek and records the various shifts in meaning through time. According to the study the initial meaning ‘quickly’, ‘immediately’ turned into ‘perhaps’, ‘maybe’ and ended up to denote allegation ‘supposedly’. The adverb underwent semantic change due to various processes such as subjectification, or else, a re-analysis of this element from the point of view of the speakers. The author explains that the adverb was found in different contexts, thus, adopting different meanings which resulted in bleaching, that is, the wearing off of the initial meaning. Occasionally, speakers were led to a different meaning due to the different pragmatic inferences they drew. Overall, the author presents the semantic load of τάχα through time and he also gives an account of its grammatical role.