def time_question_features(self, text):
        """
        Provide an analysis of significant features in the string.
        """
        features = {}

        # A list of all words from the known sentences
        all_words = " ".join(self.positive + self.negative).split()

        # A list of the first word in each of the known sentence
        all_first_words = []
        for sentence in self.positive + self.negative:
            all_first_words.append(
                sentence.split(' ', 1)[0]
            )

        for word in text.split():
            features['first_word({})'.format(word)] = (word in all_first_words)

        for word in text.split():
            features['contains({})'.format(word)] = (word in all_words)

        for letter in 'abcdefghijklmnopqrstuvwxyz':
            features['count({})'.format(letter)] = text.lower().count(letter)
            features['has({})'.format(letter)] = (letter in text.lower())

        return features
Provide an analysis of significant features in the string.