The availability of subtitles are dependent on whether the broadcaster transmits them as part of the TV signal. If the program being viewed contains subtitles you can toggle them on and off in EyeTV from the View menu. Any recordings you make of shows that were broadcast with subtitles will also have subtitles available when you play back that recording in EyeTV.
To toggle subtitles on or off just click on the EyeTV's View menu then click on "Closed Captions".
Any other questions about subtitles, teletext and closed captioning when using Elgato's EyeTV software or hardware should be directed to Elgato Technical Support at support.elgato.com
Note: Previously subtitles could be viewed in EyeTV by selecting View > Teletext > Text. (and sometimes also selecting the yellow option under that menu was needed to get subtitles working). This method no longer works as at used teletext which was discontinued in Australia during the switch to digital TV.