I'm learning haskell and having a bit of trouble understanding it. Basically, I have a program which will read in a letter, and change it if it is a consonant to a '!', however I can't seem to set the value of the character..

here's my code so far ..

```
isConsonant :: Char -> Bool
consonant_alphabet = ['b'..'d']++['f'..'h']++['j'..'n']++['p'..'t']++['v'..'z'] ++ ['B'..'D']++['F'..'H']++['J'..'N']++['P'..'T']++['V'..'Z']
isConsonant character = character `elem` consonant_alphabet

repConsonant :: Char -> String
repConsonant c =
    if isConsonant c
        then "CONVERT IT TO !"
        else do "NO CONVERSION REQUIRED"

```

I have it as a string output for debugging purposes but I can't figure this one out.. Any ideas? I've tried to do

```
let c = "!"

```