I skated for 4 hours . I have been skating for 4 hours. I have skaked . 这三句话的区别.过去式,现在完成式,现在完成进行时,之间的区别是什么

英语比较厉害的 关于 have been 的用法的~have been do sth.have been doing sth.有什么区别?比如：I skated for 4 hours.和 I have been skated for 4 hours.有什么区别? I skated for 4 hours . I have been skating for 4 hours. I have skaked . 这三句话的区别.过去式,现在完成式,现在完成进行时,之间的区别是什么 he skated for four hours 为什么加for I skated for four hours与I have been skating for four hours的区别最好详细点,说的明白点 my brother skated for the w___two hours yesterdayRT. San skated for four hours 对划线部分提问 I'm sorry that you didn't win the skating marathon .How long _you_?I've skated for 5 hours.应该填什么?不会的别乱说 现在完成时态的 I've been skating for five hours 这句是什么时态,与I've skated for five hours.有什么区别?还有 这句一般过去时 是什么含义 I skated for five hours.与第二句有什么区别？ -How long did you skate?-I skated for two hours.第一句中”did”” skate”能换成”have””been skating”?为什么? I skated but I fell down for many i've been skating for five hours=i skated for five hours 这两句是不是意思完全相同呢?顺便再说说现在完成进行时态的特点吧～· He's been studying there for （two whole hours）?对括号提问I missed the train （an hour ago） （ 同上）He skated from 7:00 to 9：00 yesterday （同上）He has been skating for four hours （否定句）He ___ ____ ____ for four hours how long did you skate?--I skated for two years.请帮忙分析一下此句话的语法I skated for two years.I have skated for five years两句有什么区分 Alison,c____winning the skating My brother skated for the w___ two hours yesterday.We started classes an hour a____. 这道英语题它的考点是什么. I’ve been ________for five hours. A. skate B. skating C. skated how long did you skate?I skated for two years.是持续的时间为何不用过去完成时. I danced for three hours last I sleep for nine hours every night