现在分词一般式doing和不定式to be doing都表示主动和与谓语动词同时发生，作状语由于意义不同可以区分，那么在作定语与宾补时两者有什么区别。比如作定语时，The man speaking to him is my father.可不可以换成The man to be speaking to him i...
agree 后接不定式的用法（agree to od sth）比较多，如：
He agree to go with us. 他同意和我们一起去。
He agreed to let me go home early. 他同意让我早些回家。
但有时也见到agree on doing sth的用法。如：
He agreed on lending us some money. 他同...
Meanwhile, I found out that with more patience I must make my toys to last. My attitude changed from then on.这是2012年的高考英语新课标卷短文改错中的一句，答案是把 must 改为 might 或 could，但为什么这里用了 to last 呢？这里的 make 是表示“使”吧，它...
老师晚上好：看到这个句子：Water is necessary for life.学生有了疑问：因为曾看到过这样的论述——主语为具体的物，介词用to。如：The book is important to me.主语为抽象的事，介词用for。如：Studyig English is important for me.望老师点拨。
Scientists may have the right to investigate anything within their means, but that does not mean that they also have the right to the means to investigate anything they choose.后半句have the right to the means to investigate中to the means是不是多余了，这里的means作何解？
有网友提出这个句子：I shouldn’t always have to tell you what to do. 网友问：shouldn't have to 是什么意思，什么情况使用它？见：http://ask.yygrammar.com/q-24691.html曹老师的解答认为：网友的这个句子：I shouldn’t always have to tell you what to...