def create_ngram(sentence: str, ngram_size: int) -> list[str]:
    """
    Create ngrams from a sentence

    >>> create_ngram("I am a sentence", 2)
    ['I ', ' a', 'am', 'm ', ' a', 'a ', ' s', 'se', 'en', 'nt', 'te', 'en', 'nc', 'ce']
    >>> create_ngram("I am an NLPer", 2)
    ['I ', ' a', 'am', 'm ', ' a', 'an', 'n ', ' N', 'NL', 'LP', 'Pe', 'er']
    >>> create_ngram("This is short", 50)
    []
    """
    return [sentence[i : i + ngram_size] for i in range(len(sentence) - ngram_size + 1)]