Korean: 3 NHSK word(s): 地铁* 3 di4 tie3subway/ metro 钢铁* 5 gang1 tie3steel 斩钉截铁* 6 zhan3 ding1 jie2 tie3to chop the nail and slice the iron (idiom)/ resolute and decisive/ unhesitating/ definitely/ without any doubt KOREAN6000 word(s): KOREAN 2500 New HSK words): KOREAN Sentence(s):