The understanding of the grammaticalization process used today is quite diverse; nevertheless it presents a great step forward in contemporary linguistics and offers almost universal criteria for its description. The grammaticalization of the analytic verbal structures and especially of Perfect tense was first observed by the pioneers of the modern grammaticalization theory (A. Meillet, J. Kurylowicz) and had since become the subject of systematic investigation. One of the constituents of the European linguistic area (ELA) is the ability to form analytical verbal constructions and verbal tenses – in the case of the Perfects predominantly as a bi-auxiliary habere/esse type, or as a mono-auxiliary habere type and esse type. The West Slavic habere Perfect constructions in Czech with their three main types show, thanks to the extensive data well documented by the Czech National Corpus, some rather unique innovations, as e.g. the shift from the object type agreement of the n-/t-participle to a subject-type agreement.