我觉得理解别人要比让别人理解自己容易，因为我对很多词的印象很模糊，在书中见到我能理解，但我想表达自己的思想时又记不住了。要改变这种状况怎样做最好?
You are quite right: understanding spoken or written text is easier than being understood when you speak or write. This is because understanding is a receptive skill, while speaking and writing are productive skills. We can always understand far more than we can produce, and this is also true when we are using our native language. Once you have accepted this reality, you should practise expressing yourself in the language that you can immediately recall. When you can’t think of the right word (which you might know receptively but fail to produce when you want it), you have to find alternative words to express your meaning. Keep listening to English and reading it as much as you can. In the long term, this will improve the way you speak and write.
你说得对：理解口语或文章要比让别人理解你说或写的东西容易。这是因为理解是一种接受性的技巧，而说和写是创造性技巧。我们能理解的远远多于我们能表达的，我们在使用母语时也是这样。你接受了这个现实之后，应该训练自己使用那些你能马上回想起的语言表达思想。你找不到恰当的词汇的时候(见到或听到时可能能理解，但需要时却用不上)，你不得不用别的词来表达你的意思。坚持听英语，尽量多地阅读。长此以往，这将提高你说和写的水平。
文：路易亚历山大 新概念英语作者