这句话能否转换成现在完成时?I have been learning English since 3 years ago.自三年前我一直在学英语.这句话能不能转换成现在完成时?能的话要怎么转换?

这句话能否转换成现在完成时?I have been learning English since 3 years ago.自三年前我一直在学英语.这句话能不能转换成现在完成时?能的话要怎么转换? I have went through many difficulties这句话对么?现在完成时的话是不是应该是i have gone through many difficulties? 现在完成时的用法I have written a book、 这句话有强调影响或结果吗?是不是一定要有影响？ 表状态情绪感觉精神活动的动词,不用现在完成时对吗～I have just arrived by train 这句话对吗 Yesterday I have come back from China.这句话里有Yesterday ,为什么还能用现在完成时呢? 英语现在完成时问题I have gone at this school since 2012.这句话为什么用at?词组不是应该是have gone 请问区别,求用例句解答. I wish I had never met you的问题这句话是什么时态?如果是现在完成时,在had前面加个have语法错误吗? 时间状语从句中的“主将从现”|,其中的“从现”包含现在完成时吗?例如：这句话I will go there directly I have finished my breakfast.从句中用现在完成时对? I have just had my lunch的句子成分在I have just had my lunch这句话中,I 是主语,have 现在完成时的标志,had lunch 的原型是have lunch 但是是现在完成时,所以have lunch 要变成had lunch ,对吗? I have met him often since I have lived here.这句话对吗?不是现在完成时中since+从句用一般过去时呀?在现在完成时中,since后的从句到底用什么时态?这儿还有一句：I have learned a lot from him since I have known 现在完成时表示将来例句When you have rested, I’ll show you the garden 这句话正不正确?不是说现在完成时不能与when连用吗?急急急！！！！！！ 顺便问一下，study的过去式是什么？应该是studied吧 i have many strong evidence to prove your mistake 我有很多有力的证据来证明你的错误!这句话用现在完成时会不会用更好一点?用现在完成时应该怎么说? Yesterday I （）my penfriend an email. A. have sent B.sent这句话是现在完成时,还是一般过去时?顺便帮我解答一下. 关于现在完成时的一个小问题I have waited (for) you for three hours.这句话中,(for) 需不需要保留?还是要省略掉? I have been up since two hours ago.为什么这句话是对的?现在完成时不是不能跟过不是不能跟过去的时间连用吗? 现在完成时与until不能连用.是这样的吗?I have't found my position until now!这句话怎么修改呢? 现在完成时I用have还是has? I an have some had 改成现在完成时