(3)但现在完成进行时并不总是具有临时的性质,如:
My mother has been teaching English for twenty years.(a)
My mother has taught English for twenty years.(b)
(a)句在此并无临时性质,但较口语化。(b)句则较为正式。又,(a)句表示动作现在仍在继续.并将延续下去,(b)句的动作是否延续下去,须由上下文决定,但在一般情况下都是延续下去的。
(4)现在完成进行时往往表示动作在重复,现在完成时则常常不带重复性。如:
Have you been meeting her lately?(a)
Have you met her lately?(b)
(a)句有"经常相会"之意,(b)句则没有。(b)句如与often,every day等时间状语连用,当然也表示动作在重复。
(5)现在完成进行时比较生动,有时含有明显的感情色彩,而现在完成时往往只说明一个事实,一种影响或结果,平铺直叙,没有什么感情色彩可言。如:
What have you been doing?(a)
What have you done?(b)
(a)句表示惊异。(b)句只是一个问题。
Have you been waiting long?(a)
Have you waited long?(b)
(a)句较(b)句生动。又,(a)句比较口语化。
I have been wanting to meet you for long.(a)
I have long wanted to meet you.(b)
(a)句比(b)句更亲切,更有礼貌。
Recently Mary has been doing her work regularly.(a)
Recently Mary has done her work regularly.(b)
(a)句显然是在表扬玛丽。(b)只说明一个事实。
下面还有一例,颇为有趣:
Who's been eating my apples?(a)
Who's eaten my apples?(b)
(a)句有强烈的感情色彩,表示愤怒不满,(b)句只是希望回答的一个问题。又,(a)句兼有进行时态,所以有"苹果未被全部吃光"的意思,(b)句是完成时态,说明"苹果一个不剩了"。