for-和since

SINCE和FOR的用法表示一个从过去开始，一直持续到现在的动作或状态。通常和for或since引导的时间状语连用。注意：动词延续性for后面表示时间的可以是具体的数字,也可以是泛指的时间,如alongtime,severaldays,sometime(一些时间)for+一段时间现在for过去IhavelivedhereShehasbeenbusyforalongtime.forfivedays.foralongtime.forfivedays.HestudiedinPekingUniversityfor4yearsin1960’s.for4yearsin1960’s.Since+表示过去的时间的词,表示从过去某时开始的动作或状态一直持续到现在,此时since是介词.常见的时间状语如:SincethreeyearsagoSincetwomonthsagoSincethen从那时以来Since2005MikehasbeensickShehasworkedasalawyersince5yearsagosinceyesterday/lastnightsinceyesterday/lastnight注：since也可单独使用,表示“自那时起”；另外since前也可加上ever，以加强语气。Ihavebeenhere(ever)sincethen.Ihavegivenupsmokingeversince.还可在since后接句子.since前加ever,只是加重语气而已.IhavegivenupsmokingThey’velivedinCQ（）sinceIcaughtabadcough.sincetheymarriedin2000.sinceIcaughtabadcough.sincetheymarriedin2000.since+句子(过去时),此过去时的句子相当于“since+表示过去的时间”只不过用过去时的动词表示过去的动作或状态,此时since是连词.Wehaveknowneachothersincewewerechildren.Wehavelivedheresincewemovedherein2001Itis/hasbeentenyearssinceweleft.自从我们离开已经有十年了.Since引导的从句中的动词用过去时,而主句原则上是用现在完成时,但itis+时间…句型除外.howlong…表示多长时间,多久.回答“howlong+have/has+主语+过去分词…”这样的现在完成时的问句时,常用for…和since…的句子.但和“for+时间”一样,howlong不仅用于完成时还可用于其他时态.A:Howlonghaveyouworkedinthisfactory?B:I’veworkedinthisfactoryfor3years.B:I’veworkedinthisfactorysinceIgraduatedfromuniversity.HowlongdidyoustudyChineselastyear?“when…?”疑问句不可以用现在完成时,因为“when…”疑问句是用来询问时间的,而现在完成时则不谈动作的具体时间.(正)WhendidyouvisitBeijing?(误)whenhaveyouvisitedBeijing?注：短暂性动词不能和for或since引导的时间状语连用，也不能用于howlong问句中。(正)Ihavebeenawayfor5years.（误）Ihaveleftfor5years.1.JimhasbeeninIreland______Monday.2.JillhasbeeninIreland______threedays.3.HisaunthaslivedinAustralia______15days.4.Maryisinheroffice.Shehasbeenthere______7o'clock.5.Indiahasbeenanindependentcountry______1974.6.Thebusislate.They'vebeenwaiting______20minutes.7.Nobodylivesinthosehouses.Theyhavebeenempty______manyyears.8.Mikehasbeenill______alongtime.Hehasbeeninhospital______October.sincesincesincesinceforforforforfor