现在完成时的句子|英语语法专练—现在完成时( 二 ) 一、结构1.主语+have「问人人知识网」

如：How long have you keep this book?/She has had the watch for three days.
四、几点注意事项
1.现在完成时态与一般过去时态的区别：现在完成时态强调动作与现在的关系，如对现在产生的结果或影响等。一般过去时态表示在过去某一时刻发生，不表示和现在的关系。如：I seen this film./I saw this film yesterday.
2.have/has been to表示去过某地（现在已经回来了），可用于各人称；have/has gone to表示去某地了（说话时某人不在现场）。常用于第三人称。have/has been in表示待在某地，一直在某地。如：They have been to Shanghai three times./They have gone to Shanghai./They have been in Shanghai for three years.
3.关于since 的几个句型：
（1）主语+have/has+动词的过去分词+since+一般过去时态的句子。如：She has been away from Shanghai since she went to college.
（2）主语+have/has+动词的过去分词+since+时间点。=It is/has been+时间+since+一般过去时态的句子。=时间has passed+since+一般过去时态的句子。如：She has worked in this hospital since ten years ago.=It is/has been ten years since she worked in this hospital.=Ten years has passed since she worked in this hospital.
4.个别短暂性动词的否定形式可以表示状态的延续，所以可以和表示一段时间的状语连用于现在完成时态中。如：We haven’t seen each other for a long time.
五、练习
（一）用括号中所给词的适当形式填空。
1.She_____(teach)English for three years.
2.People_____(celebrate)the National Day since then.
3.How long_____you_____(be)like this?
4.They____(not write)two letters since last Friday.
5.She_____(work)there for two days.
6._____you ever_____(travel)abroad?
7.I_____never_____(make)a cake by myself.
8.Recently she_____(read)two novels.
9._____she ever_____(ride) a horse?
10.They_____(not finish)the work yet.
（二）根据要求句型转换。
电路设计（16条电路设计思路）重要提示电路设计并非完全创新，更多的是对现有电路资源的有机整合和对单元电路的局部创新或变化，所以电路设计并非高不可攀、深不可及。电路设计与电路识图完全不同，电路设计是依据自己的电子技术知识水平进行思维输出的过程，识图则是知识输入的过程，两者思维方式不同。1.两种基本思想
1.They have bought a bike.（否定句）
2.She has been there twice.（划线提问）
3.They have chosen the panda to be symbol.（划线提问）
4.He has drawn three pictures these days.（划线提问）
5.Lucy has lived in Changchun for two years.（划线提问）
6.Daming has driven home.（一般疑问句）
7.Have you brought your homework to school yet?（陈述句）
8.She has sent emails to his friends.（否定句）