现在完成时的用法：since
现在完成时的第二个基本用法表示过去已经开始，持续到现在的动作或状态。该用法常和表示过去某一时刻延续到现在的一段时间的状语连用。①与for +一段时间连用，表示多久。
e.g. He has learned English for two years. 他已经学习两年英语了。
I have been here for three days. 我在这里已经3天了。
②与since +时间(起点)连用，表示自…以来。
e.g. His father has worked in that factory since 1991. 他爸爸自1991年以来都在这家工厂工作。
I’ve had a cold since last Friday. 自上星期五起我就感冒了。
③与since +一段时间+ ago连用，表示自…以前就…。
e.g. Jim has waited there since half an hour ago. 吉姆自半个小时前就已经在那里等候了。
He has stayed here since three weeks ago. 他在这儿已呆了三个星期。
④与since +从句(从句用一般过去时)连用，表示自某事发生后就一直…。
e.g.The Greens have lived in Beijng since they came to China. 格林一家自从来到中国后就一直住在北京。
I’ve known her since I came to work here. 自从我来这里工作就认识他了。
现在完成时的最后基本用法表示到现在为止这一时期中多次动作的总和或所做过的工作的量的积累。
e.g. I have been to Beijing twice. 我去过北京两次。
We’ve learnt five English songs this year. 今年我们学了五首英语歌曲。
How many pages of the book have you read? 这本书你读了多少页了?
页:
[1]