A proof of concept of a small plural sentences creator

plural_maker.hs

import qualified Data.Char as Char

data Things t = Things {thing :: t, quantity :: Int}
instance (Show t) => Show (Things t)
  where
    show t = if quantity t == 1 then get t else get t ++ "s"
      where
        get = filter (not . (`elem` "\"")) . show . thing

makeSentence :: (Show t) => [Things t -> String] -> t -> Int -> String
makeSentence ps t n = makeup . unwords . map ($ Things t n) $ ps
  where
    makeup (s:ss) = (Char.toUpper s : ss) ++ "."

things :: (Show t) => Things t -> String
things = show

thereBe :: (Show t) => Things t -> String
thereBe t
  | quantity t == 1 = "there is"
  | otherwise = "there are"

howMany :: (Show t) => Things t -> String
howMany t
  | quantity t == 0 = "no"
  | otherwise = show $ quantity t

tellHowMany :: (Show t) => t -> Int -> String
tellHowMany = makeSentence [thereBe, howMany, things]

main = do
    putStrLn $ tellHowMany "apple" 0
    putStrLn $ tellHowMany "banana" 1
    putStrLn $ tellHowMany "orange" 2