let's get things cleared first...
stands for Text-To-Speech, to get a text spoken out this function needs a VOICE...
& you got Microsofts Voice Anna (en/us) installed
Next thing is Speech Recognition
, the way your system understands what you speak...
you can take 3rd party software for that, or like you seem to do, the in-built service from Windows.
You can download different Speech-Recognition profiles incl. TTS-Voices directly from Microsoft for many languages.
the speech-recognition-profile you want to use must have the same language your OS interface is running,
so in your case - greek.
Now to your 1st problem with the Interface...it's a know bug being fixed in the future versions, see this link to fix this problem: http://www.syn.co.in/forums/viewtopic.p ... =461#p1792
2nd..you can't make the assistant speak greek yet, cause its english...it will speak greek if a translation in greek is being made, but like you may have read...multilanguage support is yet to come
You can install any voice you want though, nearly every TTS-Voice should work, no matter what language the voice is, but when your greek voice (or whatever voice you may try) is reading/speaking out the english text, it will just sound like some funny shit