1_ what are meaning these sentences? 八 点 上课，他 八 点 半 就 来 了。 he came at 8:30 -- stated action in the past 八 点 上课，他 八 点 十分 才 来。 he "managed to come" at 8:10 昨天 我 去 北京 吃饭，八 点 坐 车，八 点 半 就 到了。 yesterday i went to Beijing to have a meal, took a bus at 8, got there at 8:30 今天 我 去 诶经 吃饭，八 点 坐 车，八点 才 到。 today i went to eijing to have a means, took a bus at 8, managed to got there at 8 -- the sentence is definitely wrong (must be at least several minutes or the phrase next day) 2_in this sentences 好 meaning finished? 自行车 修好了 吗？ the result of repairment, "was the bicycle repaired?" 3_ what are meaning these sentences? 没关系 你 用 吧。 = doesn't matter, you use it. 不 用 了。 = no need