This paper discusses the conditions for the grammaticalization of evidentia
lity in different languages, with special attention to the languages of Sou
th Eastern Europe and the Middle East. In these languages, evidentially mar
ked discourse is opposed to neutral discourse, while in some other language
s, evidential markers are necessarily included in every verb form; and in o
thers, evidentiality is only lexically expressed. The last section deals wi
th the problem of cross-language comparisons of evidential systems. A few t
houghts are presented on the ques tion of how to build a set of concepts to
be used as a tertium comparationis. (C) 2001 Elsevier Science B.V. All rig
hts reserved.