第20期
语法运用 Grammar in use
一、现在完成时与since和for
上一单元我们初步学习了现在完成时, 本单元我们来学习一下由since或for引导的时间状语的现在完成时。
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since
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since+过去某个时间点。如：
I have lived here since
I was ten years old.
我从十岁时就住在这里了。
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瞬间动词不与 “since+过去某个时间点” 连用表示动作的持续性, 应改为持续性动词。如: Jack has left school since 6 o’clock. (×)
Jack has been away from school since 6 o’clock. (√)
杰克自从六点就离开学校了。
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瞬间动词的否定式可以与 “since+过去某个时间点” 或 “for+一段时间”连用, 表示某个动作不发生的状态已经持续了一段时间。如:
I haven’t met him for years.
我已经多年没见他了。
She hasn’t gone to her hometown since last year.
她从去年以来就没有回过家乡了。
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for
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for + 一段时间,如:
He has worked for seven hours without rest.他已经连续工作七小时了。
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瞬间动词不与 “for+一段时间”连用表示动作的持续性, 应改为持续性动词。如:
She has left for two hours. (×)
She has been away for two hours. (√) 她已经离开两个小时了。
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