Readthefollowingsentenceswehaveseen.Readthefollowingsentenceswehaveseen.HaveyoureadLittleWomenyet?Yes,Ihave./No,Ihaven't.HasTinareadTreasureIslandyet?Yes,shehas.Shethinksit’sfantastic.Haveyoudecidedwhichbooktowriteaboutyet?Yes,Ihave.I’vealreadyfinishedreadingit.Itwasreallygood.HaveyoureadLittleWomenyet?Yes,Ihave./No,Ihaven't.HasTinareadTreasureIslandyet?Yes,shehas.Shethinksit’sfantastic.Haveyoudecidedwhichbooktowriteaboutyet?Yes,Ihave.I’vealreadyfinishedreadingit.Itwasreallygood.用法:1.表示过去发生或已经完成的某一动作对现在造成的影响或结果。e.g.–Haveyouhadyourlunchyet?–Yes,Ihave.I’vejusthadit.(现在我不饿了。)2.表示动作或状态从过去某一时刻开始，一直延续到现在，而且可能还要继续下去。用法:1.表示过去发生或已经完成的某一动作对现在造成的影响或结果。e.g.–Haveyouhadyourlunchyet?–Yes,Ihave.I’vejusthadit.(现在我不饿了。)2.表示动作或状态从过去某一时刻开始，一直延续到现在，而且可能还要继续下去。e.g.Ihaven’tseenherthesedays.I’veknownBobforthreeyears.I’vebeenatthisschoolforovertwoyears.e.g.Ihaven’tseenherthesedays.I’veknownBobforthreeyears.I’vebeenatthisschoolforovertwoyears.时间状语：already,yet,just,ever,never,before时间状语：already,yet,just,ever,never,before构成：现在完成时是由“助动词have/has+动词的过去分词”构成的，规则动词的过去分词构成与过去式相同，不规则动词的过去分词则需逐个记忆。构成：现在完成时是由“助动词have/has+动词的过去分词”构成的，规则动词的过去分词构成与过去式相同，不规则动词的过去分词则需逐个记忆。动词的过去式的变化和过去分词的变化并不完全相同。我们对它们作了一个大致的分类。(注：例子中单词的变化顺序为：动词原形→动词的过去式→动词的过去分词)动词的过去式的变化和过去分词的变化并不完全相同。我们对它们作了一个大致的分类。(注：例子中单词的变化顺序为：动词原形→动词的过去式→动词的过去分词)一、过去式和过去分词的变化相同规则变化：1.一般在动词词尾直接加ed。如：pick→picked→picked;wish→wished→wished;stay→stayed→stayed2.以不发音的e结尾的动词后面加d。如：like→liked→liked;hope→hoped→hoped;phone→phoned→phoned一、过去式和过去分词的变化相同规则变化：1.一般在动词词尾直接加ed。如：pick→picked→picked;wish→wished→wished;stay→stayed→stayed2.以不发音的e结尾的动词后面加d。如：like→liked→liked;hope→hoped→hoped;phone→phoned→phoned3.以“辅音字母+y”结尾的动词，变y为i，再加-ed。如：study→studied→studied;hurry→hurried→hurried;reply→replied→replied4.词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。如：stop→stopped→stopped;clap→clapped→clapped3.以“辅音字母+y”结尾的动词，变y为i，再加-ed。如：study→studied→studied;hurry→hurried→hurried;reply→replied→replied4.词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。如：stop→stopped→stopped;clap→clapped→clapped不规则变化：5.以不变应万变。如：let→let→let;put→put→put;read→read→read6.若中间有双写e，则去掉一个e，单词末尾再加t。如：feel→felt→felt;keep→kept→kept;sleep→slept→slept不规则变化：5.以不变应万变。如：let→let→let;put→put→put;read→read→read6.若中间有双写e，则去掉一个e，单词末尾再加t。如：feel→felt→felt;keep→kept→kept;sleep→slept→slept7.结尾的字母d变t。如：lend→lent→lent;build→built→built;send→sent→sent8.变为以-ought或-aught结尾。如：buy→bought→bought;bring→brought→brought;catch→caught→caught;teach→taught→taught7.结尾的字母d变t。如：lend→lent→lent;build→built→built;send→sent→sent8.变为以-ought或-aught结尾。如：buy→bought...
