can i use a string as a whole string after cutting it to head and tails (a:as) and using recursion on it in Haskell?

Question

I am trying to use every character in the string in a function i have (that uses only one Char) but i am also trying to use that same string as a whole in the same recursive function to compare it to indvidual characters in another string (using elem). Is there a way i can use that string heads and tails and also the whole string, so that the string will not be cut after every recursion?

Code:

checkTrue :: TrueChar -> Char -> [Char] -> TruthValue
checkTrue a b c
            | a == IsTrue b                             = AbsoluteTrue
            | (a == IsFalse b) && (b `elem` c)          = PartialTrue
            | otherwise                                 = NoneTrue

checkTruths :: [TrueChar] -> [Char] -> [TruthValue]
checkTruths [][] = []
checkTruths (a:as) (b:bs) = checkTrue a b (removeAbsoluteTrue (a:as) (b:bs)): checkTruths as bs 
{-  This is the line, 
i wanted to use b as a string and also as b:bs. is this possible? -}
checkTruths _ _ = [NoneTrue]