No output in 'english word generator'

[DeGerlash]

Wow I didn't know that was all done already. Great! I'm trying to get better though. At this instance, after some research, I've managed to change my isValid() function to:

def isValid(word):
    file = open("wordsEn.txt", "r")
    for element in file.readlines():
        if element==word:
            return True
        else:
            return False

Though, if I test it with, for example, "extinguisher", it results me 'False'. This is strange, as the word 'extinguisher' is certainly in the list (I've looked it up). I don't really see what I'm doing wrong here :/