a simple question about def function (if word starts with "pre" return "valid) : I am a beginner. Could you please help me to check what's wrong with my code. Thank you very much!!!

question: ask people to enter a word, if it starts with "pre" return "valid". otherwise, print "not valid".

    def word_fun(word):
        word = input("enter a word: ").lower()
        if word.startswith("pre") and word.isalpha:
            print("valid")
        else:
            print("not valid")
    word_fun(word)

