-kah has not been introduced before. What does it mean?
It function to stress the question like, " are you really really really really sure?" :)
Note that without the "-kah", the answer is also correct as long as your intonation is right
Lessons have an odd mixture of formal Indonesian (Benarkah? instead of Betul?) and informal (kamu instead of anda).
I have NEVER heard anyone say "benarkah"
People say just "benar" or maybe¨ yang benar aja¨ :-)
I'm confused as the answer required was "sungguh" but this wasn't shown as one of the possible translations in the exercise, nor is it shown here in the comments.
Pimsleur suggested "yang benar?" as a translation of "really?"
Is this correct?