not distinguish between right and wrong ❍ 你哥哥～，跟我吵了半天，我没法说服他。Your brother failed to distinguish between right and wrong. He had a long row with me and I could not persuade him.
曲直不分qū zhí bù fēn
形容分不清是非好坏。not distinguish between right and wrong, not distinguish between truth and false