Is there a difference between ほんとう (hontō) and ほんとうに (hontō-ni) when used alone as interjection or question?
As the equivalent of Enlgish "Oh really?" / "Yes really." as lone utterances I seem to hear both "本当" (hontō) and "本当に" (hontō-ni) in Japanese - is there a difference? It seems that hontō is a noun ...