def extract_ngrams_to_validate_tail(ngram):
    """Extracts ngram that consistes with [:-1] tokens (removing first token)
       to check if it exists from the n-gram extraction from previous iteration

    Args:
        ngram (str): ngrams to check
    
    Returns:
        str: ngram with [1:] tokens
    """
    if not ngram or len(ngram.split(" ")) <= 1:
        return ""
    return " ".join(ngram.split(" ")[:-1])