当前位置: > since和for的区别...
题目
since和for的区别
如何使用.和时态的区别.要说的直白一点,

提问时间:2021-03-11

答案
Since 用来说明动作起始时间,for用来说明动作延续时间长度.例如:
I have lived here for more than twenty years.我住在这儿二十多年了.
I have lived here since I was born.我从出生起就住在这儿了.
注意:并非有for 作为时间状语的句子都用现在完成时.
I worked here for more than twenty years.(我现在已不在这里工作.)
I have worked here for many years.(现在我仍在这里工作.)
注意:用句型转换的方法,很容易排除非延续动词在有for/since结构的完成时中的误用.
1)(对) Tom has studied Russian for three years.= Tom began to study Russian three years ago,and is still studying it now.
2)(错) Harry has got married for six years.= Harry began to get married six years ago,and is still getting married now.
显然,第二句不对,它应改为 Harry got married six years ago.或 Harry has been married for six years.
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
奥巴马演讲不用看稿子.为什么中国领导演讲要看?
想找英语初三上学期的首字母填空练习……
英语翻译
版权所有 CopyRight © 2012-2019 超级试练试题库 All Rights Reserved.