Tense問題

Present Perfect Tense,

It is used when something has happened and it is related to the present time.(指示發生了的事情和現在有關)

e.g. I lost my keys.
Lost在這句子中是past tense(已過去), 意思是丟失鎖匙與現在無關, 言下之意即已找回鎖匙.

e.g. I have lost my keys.
Have lost 是present perfect tense, 雖然丟失鎖匙已發生, 但現在仍然是丟失中, 言下之意即是說还沒有找到.

不同的Tenses 的分別主要是implied message 不同.


Past Perfect Tense

It is used to indicate the order of 2 actions happened.

用past perfect tense 有個首要條件, 就是整個涉及的時空只能是過去了的, (e.g. 如記叙文, 整個文章是繯繞過去, 所以整體上用past tense) 不能涉及現在.

Example,

I stayed at home yesterday. I had done my homework before I watched TV.

首先, yesterday 已指示所有句子中的動作與現在無關, 所以基本上以past tense 為主.

但句子的意思是先完成功課, 然後才看電視, 所以要用past perfect 來指示先發生動作, 後發生動作用simple past.

如果兩個動詞都用simple past, 那就变成兩個動作是同時發生, 便會與連接詞before的意思不符.

In other words, 在叙述已過去與現在無關的事情, 先發生的動作用past perfect, 後發生的動作用simple past.

請注意, 如果先做完功課後看電視是一種習慣, 那便會涉及現在式(present tense is also used to indicate something as a habit). 那麼, 先發生的動作用present perfect, 後發生的動作用simple present.

大致上是這些分別, 如有further questions 請再發問.

hi....
when the thing JUST finished, you should use the present perfect tense. e.g. Peter has finished his homework.
when the thing was finished for a long time, use past perfect tense. e.g. Peter had finished his project yesterday.
Hope it can help you.

We use present perfect tense to talk about
*actions that have just finished
*things that started in the past and continue to the present
The tence has two words: has/have +past participle.

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