def make_constructed_utts(utt_tokens):
    """
    Converts utterances into correct form for composition
    Args:
        utt_tokens: List of utterances (utterance = list of tokens)

    Returns: 
        utts:
            List of utterances for individual tokens and compositions
        compose_idx:
            List of indices in utts to be composed
        [["green", "-ish"]] => 
        [["#start#", "green", "#end#"],
         ["#start#", "-ish", "#end#"],
         ["#start#", "green", "-ish", "#end#"]], 
        [(0,2)]

    """
    START = "#start#"
    END = "#end#"
    utts = []
    compose_idx = []
    for utt in utt_tokens:
        compose_idx.append((len(utts), len(utts)+len(utt))) # [start, end)
        for tok in utt:
            utts.append([START, tok, END])
        utts.append([START] + utt + [END])
    return utts, compose_idx