SectionⅢGrammar——现在完成时和现在完成进行时语境自主领悟先观察原句后自主感悟①Ihaven'tseenJustinsince
②DetectiveSamPeterson,whohastakenchargeofthecase,toldjournalists,‘Sometimespeoplemakeupsuchamazingstories
’③Fromourrecentsurveyofstudents,wehavefoundthat53percentofthestudentsoftenplaysports
④Forcenturies,peoplehavereportedseeingawildcreatureintheHimalayascalledYeti
⑤LargetrackshavealsobeendiscoveredwhichsomepeoplesaybelongtotheWildMan
⑥Thisincidenthasreceivedgreatinterestduetoreportsofstrangelightsintheskyandofalienvisitsaroundthetimetheboydisappeared
⑦I'vebeenwritingthecompositionfortwohours,butIhaven'tfinishedityet
⑧Ihavebeenwantingtomeetyouforalongtime
句①~⑥中均运用了现在完成时,其谓语动词的构成形式为:have/has+过去分词
句⑦⑧运用了现在完成进行时,其谓语动词的构成形式为:have/has+been+现在分词,表示过去发生的动作一直持续到现在
现在完成时有两个基本用法:一是表示过去发生的动作对现在造成的影响或结果,如句②③