有一d問題關於現在完成式問題想問

present perfect tense is used to describe
1) action that began in the past and continue in the present (what you say so)
2) recently completed actions
3) actions or events that happened at an unspecific time in the past
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It is difficult to differentiate (1), (2) or (3) by one sentence.

現在完成式對現在係有影响
geo****** 理解無錯

現在完成式表結果 (result)
它的動作發生在過去, 但對現在有影响
這影响往往是說話人的興趣所在

例子
The avalanche (雪崩) has devastated (摧毀) the skiing industry in the area.
(result = the skiing industry is still big problems.)

2014-04-07 05:59:55 補充：
現在完成式不單是講述或表達剛完成/已完成的事，還可以表持續性,
要看如何用

He has lived in London for ten years.
他居住倫敦至今已十年
~ 不是現在不住, 多數繼續住, 打算住落去
除非另外 clause 表明今後去向

I am afraid that Jenkin messes up the tense.

The Present Perfect Tense,indicates an action took in past, is associated with the Present Idea of NOW,eg:-
I have turned off my television.(Up to now)
The Present Perfect Tense is used:-
(1) For an action just concluded when the resulting state-conditioned state is still present,eg:-
I have turned off my television; I am unable to see any pictures.
With activities completed in the immediate past, just is often used, eg:-The TV has just turned off.
Note that though just is an adverbial of the present, just now(=a little time ago) is an adverbial of the past and the verb used with it would be a Past Tense, eg:-
The tv shut just now.
(2)For duration of an action or of absence of an action begun in the past and continuing to the present (and possibly to the future), eg:-
I have just turned off my TV for (00:01-00;00=00:01 sec.)say you used 0.01 sec.,(and am still seeing no pictures)
Compare this with eg:-
I saw the Dr.this morning already(and no longer need any TV)for my forced psychological condition subjective to The simple present perfect tense,.mentally which I can only posted-asked The Simple Tense !

朋友，同類問題你問了幾十次，我懷疑你對tenses有強逼性心理障礙，建議你找精神科醫生檢查一下。

句子寫法和意思"咁即係宜家部電視機無畫面啦"都正確，但係理解上"現在完成式對宜家係有影响既"就未必正確-問題是"有影響"這個詞的意思。

現在完成式只是講述或表達剛完成/已完成的事，內容不會影響現在的狀況，應該是反映/表述這狀況發生的時間性。

[有些同學仔難以理解現在完成式跟過去式的表達分別就是這原因 - 因為中文兩樣都好似講成係"已經關了"。不在這裏詳解simple past tense/present perfect tense/past perfect tense的分別了-你有興趣便自己去了解一下當中的特性。]