Abstrakt
The paper offers five diachronic case studies which regard to the formation and development of several Czech modal expressions and it takes the German influence on the Czech modality system into consideration. In the studies about the verbs mít 'should' and potřebovat 'to need', used as a conditional marker and as a deontic modal verb, respectivelly, two semantic loans of peripheral modal meaning are demonstrated.
The studies about hodlat 'to want (to do sth.)' and uspět 'to succeed in sth.' as well as about the modal adverb možná 'maybe' prove the development to and from a modal meaning/function. In the last study, semantic parallels between Czech modal particle také and German auch 'also, too, as well' are proposed to be explained with diachronic relationships of both languages.