i have learned it since three years ago.这里since做介词?three years ago不是副词吗?很疑惑 如果是for three years.这里 three years是名词?另问一个问题 young sister和younger sister有什么区别？可以用young sister 表达

i learned english for four years,but i have forgotten most of it.为什么不能用 have learned呢?这句话前面的learned,为什么不能用 have learned呢? I have learned English for eight years,I cant use it very well改一个错 Know?I would like you just do not know when you have learned to understand it i have learned [ ]it from my teachera much b a lot of. I have learned a ( ) from you. I [ ] English for three years 1.learn 2.learned 3.have learned 4.has learned Have you learned German?Yes.It's___ language I've ever learned.A.a quite difficultB.quite a difficultC.difficult quiteD.difficult a quiteA＆B有什么区别. What I have learned from the friends I have made I don't wanted to have learned English.I wanted not to have learned English. It was great and I think I learned a lot.和It was great and I think I have learned a lot.强调的各是什么 有什么区别 I have learned English 变为过去式 时,have用变吗? I think i have learned a lot today是什么句式? i have been learned English before. i had been learned English before. 有什么分别? I have never learned as much math in my life as I did last year.It was because of Ms.Vacirca 51 I就是这篇完形的翻译， I have ____ the mistakes in the last exams and I will not make the same mistake.A.learned of B.learned about C.learned D.learned from how do you like your english?选出最佳答语选出最佳答语A i have learned it for two yearsB my english is very goodC it's boring -Have you _____ learned English?-Yes,I’ve _ ___ learned a lot. learned,about China,a lot,I,have,the Internet,from