▲薄冰英语语法(p405)
有读者提出现在完成时如无for或since所引导的状语所修饰其动作是否会延续下去这样的问题。
一般来说，如果没有for或since引导的状语，现在完成时所表的动作或状态，皆已完成或结束，只是其结果仍影响于现在。如：
(1) He has gone. （动作已结束，含义是 he is not here now）
(2) She has been ill. （病的状态已结束。含义是 That’s why she looks pale）
▲但不可绝对化，例外还是有的，虽然为数较少，比较常见的有下面两种：
- 在连词引导的状语从句中，完成时态所表的动作或状态有时仍在延续。如：
(3) There have not been many visitors since we have lived here.
(4) He has visited me quite often since I have been ill.
(5) I have gone camping twice since I have owned a bike.
(6) Her English writing has improved a lot since she has kept a diary in English.
(7) He has been grey-headed ever since I have known him.
这五个例子，完成式动词都是持续动词。
这是不是说since从句中的现在完成时所表的动作都会无例外地延续下去呢？事实并非如此，试举两三个例外如下：
(8) It’s a long time since I have seen you. (注意see 不是持续动词)
(9) It’s an age since you have been here.
(10) It’s now four years since I have studied this question.
据一位英语语法学家说，英语里只有continuous一词的完成式可以表示其动作或状态仍在延续。
如：
(11) In thePhilippinesthe typhoon has continuous north.
(12) He has remained neutral.
此外，我还发现了一个例句：
You’ve been out, Sophia? (Bennet) 现代英语用法词典(张道真) p965-966
