save the following as utf-8

    dvě dvojtečky

    dve dvotačke
    
    dve dvotočke

    tuu kooloons

hear it

czech robot male eSpeak\command_line\espeak.exe -v cs+m2 -f textfile.txt

czech robot female eSpeak\command_line\espeak.exe -v cs+f2 -f textfile.txt

Compare to espeak.exe -v en-us+m1 "two colons"