Question

独立主格 时态The last bus having gone, we had to walk home.为什么用having gone

All the money having been spent,we started looking for work.为什么用having been spent
不是问被动，而是完成进行时

Answer 1

用 having gone【v-ing形式的完成式】原因分步理解：
首先，独立主格结构，结构中要用非谓语动词。
其次，非谓语动词的具体形式，要根据独立结构的名词确定。名词和该动词是主动关系，就用v-ing形式。
第三，与谓语动词动作比较，判断动作的先后关系。非谓语动词的动作在谓语动词动作之前完成或发生，就要用非谓语动词的完成式。
四，句子意思：
由于最后一班公交车【已经开走】，我们只能【步行回家】。有明确先后关系。
五，替换理解：
The last bus having gone, we had to walk home.

=With the last bus having gone,we had to walk home.
=As the last had gone,we had to walk home.
=The last had gone,so we had to walk home.
祝你开心如意！

追问

All the money having been spent,we started looking for work.
其次，非谓语动词的具体形式，要根据独立结构的名词确定。名词和该动词是被动关系，就用ved形式。对吧？那么，All the money had been spent,we started looking for work.

追答

All the money had been spent,we started looking for work.
没有连词啊，你给的肯定错了！我给的里面都有连词！

不过可以修改正确：
All the money had been spent,【so】we started looking for work

=【As】all the money had been spent,we started looking for work
=All the money having been spent,we started looking for work
=With all the money had been spent,we started looking for work
独立结构使用的条件：
①句子有两部分，并且各有自己的【主体名词】（后面的名词就是句子主语）；
②两部分之间在语义上，一般存在因果、条件、让步等关系。
例如：
It 【being】a hot day, they went swimming.
=As it was a hot day,they went swimming.
=It was a hot day,so they went swimming.
The homework having been finished,the boy went out happily to play.
=As the homework had been finished,the boy went out happily to play.

Answer 2

这是个独立主格结构，表示该动作发生在主句动作之前，故用完成时，而且the last bus与gong之间是主动关系，所以用having gone,而后一句All the money与 spent是被动关系且All the money having been spent发生在we started looking for work.动作之前，故用完成时。

Answer 3

The last bus having gone, we had to walk home.这里用having gone，是指上一辆车刚刚走，是现在完成时。
All the money having been spent,we started looking for work.这里用having been spent是现在完成时的被动语态，指所有的钱刚刚被花光了。

Answer 4

因为强调动作发生在 句子谓语动作之前 所以用现在分词的完成形式 作状语
一般都是 表示原因的 是原因状语

追问

为什么不省略having？The job finished, we went home.

追答

如果The job finished, we went home用 过去分词 的独立主格结构 作状语 则是 时间状语 表示动作相继发生

不是省略 having的问题
having done是现在分词 的完成形式 与逻辑主语是主动关系
一般形式是doing
done 是过去分词 与逻辑主语是被动关系
你的句子 第一句 如果 不用having gone 也应该是 going
第二句 如果不用 having been spent ,也应该是spent
不用 后者 是为了 强调动作发生在前
如果用后者 则是 同时发生 或相继发生。