Greeks can say Είν' ο σκύλος του, but the voice really doesn't. The αι is perfectly there.
Well, that wouldn't make much sense, would it? :P
It might be because of the way the words are accented, as well as the way some vowels "clash". It sounds a bit weird, but not too weird. This is one of the problems with a Text-To-Speech program. There's always going to be a phrase/letter/syllable that doesn't sound completely natural. :/
I wrote "It is her dog" which was wrong. How do I know what gender the owner is?
Ooohhhhhh...right. Here I was thinking the του had to correspond to the thing, not the owner (like δικοι). This lesson just made a whole lot more sense, thanks!
'His dog' should be accepted
That did not translate the verb είναι.
his dog = ο σκύλος του
But είναι ο σκύλος του = it is his dog.