[Haskell-beginners] "Couldn't match expected type" and simple "Couldn't match type"

[Ken Kawamoto]

Hi Haskellers,

I found GHC sometimes complains
"Couldn't match expected type X with actual type Y"
, and simply
"Couldn't match type X with Y"
in other cases.

not a big deal, but was wondering what makes this difference.

-- Ken