def parse_metadata_words(language='english', quality='low'):
    """
    Identifies words corresponding to different metadata in the language
    Parameters:
    -----------------------------------
    language : str
        Name of the language whose testing data to fetch
    quality : str
        size of the dataset to consider

    Returns:
    -----------------------------------
    metadata_words : dict
        A dictionary with all the words grouped by metadata
    """
    metadata_words = {}
    filepath = "psynlp/data/{}-train-{}".format(language, quality)
    file = open(filepath, 'r')
    for line in file.readlines():
        source, dest, metadata = line.split("\t")
        if "*" not in source and "*" not in dest:
            metadata = metadata.strip()
            if metadata in metadata_words:
                metadata_words[metadata].append((source, dest))
            else:
                metadata_words[metadata] = []
    return metadata_words