:param str word: Thai word to be romanized, should have already been tokenized.
    :return: Spells out how the Thai word should be pronounced.

def _romanize(word: str) -> str:
    """
    :param str word: Thai word to be romanized, should have already been tokenized.
    :return: Spells out how the Thai word should be pronounced.
    """
    if not isinstance(word, str) or not word:
        return ""

    word = _replace_vowels(_normalize(word))
    res = _RE_CONSONANT.findall(word)

    # 2-character word, all consonants
    if len(word) == 2 and len(res) == 2:
        word = list(word)
        word.insert(1, "o")
        word = "".join(word)

    word = _replace_consonants(word, res)

    return word