Trying to model playing cards in Haskell(not sure this is right)

cards.hs

-- | Main entry point to the application.
module Main where

data Suit = Hearts | Dimonds | Clubs | Spades
data Rank = A | R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | J | Q | K
data Card = Card Rank Suit

rankWord :: Rank -> String
rankWord   A = "Ace"
rankWord  R2 = "Two"
rankWord  R3 = "Three"
rankWord  R4 = "Four"
rankWord  R5 = "Five"
rankWord  R6 = "Six"
rankWord  R7 = "Seven"
rankWord  R8 = "Eight"
rankWord  R9 = "Nine"
rankWord R10 = "Ten"
rankWord   J = "Jack"
rankWord   Q = "Queen"
rankWord   K = "King"

suitWord :: Suit -> String
suitWord Hearts = "Hearts"
suitWord Dimonds = "Dimonds"
suitWord Clubs = "Clubs"
suitWord Spades = "Spades"

cardWord :: Card -> String
cardWord (Card r s) = do
    let rank = rankWord r
        suit = suitWord s
    rank ++ " of " ++ suit

-- | The main entry point.
main :: IO ()
main = do
    let card = Card A Spades
        word = cardWord card
    putStrLn word