def get_words(utterance):
    """Splits an utterance into words, removes some characters not available in spoken dialogue systems,
    uppercases the text.

    :param utterance: a string
    :return: a list of string (words)
    """
    for c in '?!.,':
        utterance = utterance.replace(c, ' ').replace('  ', ' ')

    return utterance.lower().split()