def lower_first_transform(word: str, index: int):
    """
    Lower-case the first word in a series of words

    Parameters
    ----------
    word : str
        Word to lower or upper case.
    index : int
        Index of word in original string of words. If `index == 0`, `word`
        will be lower-cased, every other word will be capitalized.

    Returns
    -------
    w : str
        Transformed word.
    """
    return word.lower() if index == 0 else word.capitalize()
