He studied Czech and Russian at the Faculty of Arts in Brno, where he also worked scientifically and pedagogically throughout his life. He began his scientific activity with works on the Czech language of the National Revival period. He then focused his research particularly on contemporary Czech, especially on sentence syntax and utterance, including in the confrontational aspects of Slavic studies; he repeatedly returned to the issues of sentence semantics and pragmatics. Notably, his application of speech act theory is significant. In theory, he followed the traditions of Prague functional structuralism. Professor Grepl also engaged in intensive scientific and organizational activities, including serving as the scientific secretary of the International Commission for the Study of Slavic Languages and as the organizer of international syntactic symposia at the Faculty of Arts in Brno. From 1984 to 1989, he served as the head of the Department of Bohemian Studies. Among his extensive scientific works, the most important are the Bohemian studies published together with Professor Petr Karlík, such as Gramatické prostředky hierarchizace sémantické struktury věty (1983), Skladba spisovné češtiny (1986), and Skladba češtiny (1998). He also engaged in the popularization of linguistic Bohemian studies, for example, in the magazine Universitas.

L.: P. Karlík, ČJL 39, 1988–89, 372–375; idem, SaS 50, 1989, 171–174; idem, SPFFBU A 37–38, 1989–90, 15–20 (there also a bibliography); R. Večerka, NŘ 72, 1989, 259–261; (supplement to the bibliography), SPFFBU A 47, 1999, 202–203; (supplement to the bibliography), SPFFBU A 52, 2004, 181–182.