I didn't understand和I don't understand有什么区别请大家分析一下他们有什么区别吗?一般情况下可以互用吗?哪种比较适合口语中,或者说比较常用呢?谢谢!

He said something () i didn't understand. I didn't understand what you said.(同义句转换） I didn't understand () () I didn't quite understand what u said 翻译 ：I just didn't understand how that was fair. Sorry,I didn't understand you said翻译一下 I hope you understand me and didn't mean that. Please say a_____.I didn't understand you just now i didn't understand the problem until it_____(explan) again I didn't really understand 我不太懂 I really didn'tI didn't really understand我不太懂I really didn't understand这两个句型都是正确的嘛各位亲? I feel now the truth of these words ,which i didn't understand before.. I didn't understand和I don't understand有什么区别请大家分析一下他们有什么区别吗?一般情况下可以互用吗?哪种比较适合口语中,或者说比较常用呢?谢谢! I don't understand you. 和 I don't your understand哪个对?为什么? I didn't understand, now know that love a person will always see only merit是什么意思? I didn't understand what you said it's too hard I didn't understand what you said it's too hard You didn’t understand what I said,for you _______ to me just now ______I didn't understand thewords,I knew what he wanted?A.BecauseB.UnlessC.Even ifD.If Could you_that in English?I didn't understand what you sald.填空