Using return vs. not using return in the list monad

Question

I started my Grand Haskell Crusade (GHC :) ) and I am a bit confused with monads and IO functions. Could anyone explain simply what is the difference between those

Answer 1

My understanding is that doing

return [1,2] when in the List monad is the same as doing

func :: Maybe (Maybe Int)
func = return $ Just 1

which is why you end up with wrapped lists, as [] are just syntactic sugar right?

When really he wanted to do

func :: Maybe Int
func = return 5

or

func = Just 5

Its a bit easier to see whats going on with the Maybe monad I think.

So when you do

return [1,2]

You are doing the same as

[ [1,2] ]