def build_vocab(sentences, verbose =  True):
    """
    build_vocab builds a ordered dictionary of words and their frequency in your text corpus.
    :param sentences: list of list of words
    :return: dictionary of words and their count
    """
    vocab = {}
    for sentence in sentences:
        for word in sentence:
            try:
                vocab[word] += 1
            except KeyError:
                vocab[word] = 1
    return vocab