Question

现在完成时的几个问题

句式为have++过去分词
为什么说他死了要用he has been die而不用he has died？
还有，有一个句式是he has already finished his homework,可不可以把already置后？

Answer 1

在肯定式的现在完成时里，瞬间动词不能与表示时间段的状语连用，而应把瞬间性动词改为同义的延续性动词(组），常见瞬间动词有：die（死）, come（来）, go（去）, leave（离开）, arrive（到达）, begin（开始）, buy（买）, join（加入）, borrow（借入）, return（归还）等10个动词。
这10个瞬间性动词可用两句口诀来帮助记：
开始离去，借来还，
出生入死，买到家。
各词改为相应的延续性动词为：begin—be on, leave—be away from, borrow—keep, go—be, come—be here, return—be back, join—be in, die—be dead, buy—have, arrive—be here等。
如： 那个老头死了两年了。
（误）The old man has died for two years.
（正）The old man has been dead for two years.
（正）The old man died two years ago.
他参军五年了。
（误）He has joined the army for five years.
（正）He has been in the army for five years.
（正）He joined the army five years ago.

有些英语动词表示的行为是不能延续的，被称为终止性动词，也叫瞬间性动词和非延续性动词。这类动词不能用于“现在完成时+for引导的‘时间状语’”这一结构中充任非否定谓语。如：
那老人死了五个月了。
（误）The old man has died for five months.
（正）The old man has been dead for five months.
因为die是终止性动词，一个人从活着到死亡的变化是转瞬之间就完成的，不具有延续性，哪能延续五个月呢？而die改为延续性动词be，表示存在的状态，这就讲得通。如果非要用die来讲不可，那就得改变时态和句型，可以将上例说成：
The old man died five months ago. 或者：It’s five months since the old man died.

在现在完成时里，already 一般都放在助动词have/has与实义动词之间的。

Answer 2

他死了 - he is dead, he was dead， he has died
没有 he has been die 这说法

他已死了两年 - He has been dead for two years.

he has already finished his homework
he has finished his homework already
一样的

Answer 3

die 是短暂性的动作．死了就是一瞬间的动作．

he has been dead强调的是死的状态．状态是可延续的．用了完成时

但死这个动作．是短暂的．应该说he died

already是中位状语．位置大多放在助动词和实义动词中间