现在完成时态1.用法：①过去发生的动作对现在造成的影响或结果：强调结果例：YesterdayIfinishedmyhomework,that’stosay,Ihavefinishedmyhomeworknow.②过去已经开始一直持续到现在的动作或状态：强调继续例：Ihavelivedheresince1990.2.现在完成时的构成have\has+过去分词3.现在完成时的四个基本句型肯定句Hehasfinishedthework.一般疑问句Hashefinishedthework?否定句Hehasnotfinishedthework.两回答Yes,hehas.No,hehasn’t.特殊疑问句Whathashedone?4.在下列情形下用现在完成时1九词语①already已经肯定句中或句尾例:Ihavealreadyfoundmypen.=Ihavefoundmypenalready.②yet已经否定句和疑问句句尾例：Ihavenotfinishedtheworkyet.Haveyouboughtacomputeryet?③ever曾经句中例：Haveyoueverseenpandas?④never从不句中例：IhaveneverbeentoBeijing.⑤just刚刚句中例：Ihavejustdonemywork.⑥before以前句尾例：Ihaveneverbeentherebefore.⑦sofar到目前为止例：Sofarhehaslearnt200words.⑧howlong多久例：Howlonghaveyoulivedhere?⑨howmanytimes多少次例：HowmanytimeshashebeentoBeijing?2两词组have<has>goneto去了某地例：HehasgonetoBeijing(去了北京)have<has>beento去过某地例：HehasbeentoBeijing.(去过北京)3两结构fortwomonthsfor+一段时间Jimhaslivedherefor2months.sincelastyearsince+过去点时间LucyhasbeeninBeijingsince3yearsago.since3yearsagosince1990sincehecameheresince+过去时态句子HehasbeeninChinasincehecamehere.4如果句子里面没有时间状语，汉语意思能够加“已经”，往往用现在完成时态。例：Haveyoulostyourlibrarybook?你已经弄丢了从图书馆借的那本书吗？5现在完成时态还常常用于下列句型Theyhaveplantedmanytreesinthelastfewyears.在过去的几年，他们已经种了很多树。ThisisthebestbookIhaveeverread.这是我曾经读过的最好的一本书。ItisthefirsttimeIhaveplayedthecomputergames.这是我第一次玩电脑游戏。5.在现在完成时中，一次性动词不能和一段时间状语连用例：Hehasboughtthebookfor3years.（错）因buy这个一次性动词不能和一段时间for3years连用,改正的办法有五种：①Hehasboughtthebook..(去掉一段时间for3years)②Heboughtthebook3yearsago(改为一般过去时，使句子的意思不变)③It’s3yearssinceheboughtthebook.=3yearshaspassedsinceheboughtthebook.（改为固定句型Itis---since---）④Hehasnotboughtthebookfor3years.（改为否定句）⑤Hehashadthebookfor3years.（用延续性动词have代替buy）6.还有其他一次性动词也是这种情况，可参照前面的五种办法改正，前四种改法都一样，第五种改法各不相同，举例如下：①come/arrive/getto/reach→behere例：Ihavecomeherefor3years.（错）改为：Ihavebeenherefor3years.②leave/go→beaway例：Hehasleftfor3hours.（错）改为：Hehasbeenawayfor3hours.③begin/start→beon例：Thefilmhas