一、概念：有時一個名詞/代詞 + 一個其他結構,在句中作狀語,相當于一個狀語從句或并列句,人們通常稱這種結構為獨立主格或獨立結構.
二、獨立主格的結構：
n/pron + doing River rising,they had to left for safety.
to do Much work to do,they had to work for extra hours.
done All the work done,they went for lunch.
adj.He entered the room,his nose red with cold.
adv.He was lying in bed,light on.
Prepositional phrase He walked in,cane in hand.
在這種結構中,n/pron.在邏輯上是后一部分的主語,后一部分相當于謂語或表語.這種結構在句子中只能作狀語,
三、獨立主格在句中通常充當以下狀語成分：
1、 伴隨狀語（方式狀語）：相當于一個并列句.
He was watching TV,his mouth half open.
He fell to the ground,blood coming down his nose.
The policeman entered the dark room,gun in hand.
The old man sat down,his face pale with pain.
2、 時間狀語：相當于一個時間狀語從句.
Meeting over,everyone tried to do something for the project.
Spring coming,the flowers are coming out.
The problem settled,everyone was filled with joy.
3、 原因狀語：相當于一個原因狀語從句.
John (being) away,Tom had to do the work on his own.
It being dark,they had to walk with the torches on.
There being no bus,they had no choice but to take a taxi.
4、 條件狀語：相當于一個條件狀語從句.
Weather permitting,we’ll have a picnic this Sunday.
Enough time given,we’ll do the job better.
注：有時可以在獨立主格前面加上介詞with,構成with +復合賓語結構.
如：With the problem settled,the computer restarted.
With the old man leading,we had no difficulty finding the old Red Army man’s house.
You should not speak to others with your mouth full of food.
He left the bathroom,with the water running.
He rushed out with a knife in his hand.此句可改寫為 He rushed out ,a knife in his hand.或 He rushed out,knife in hand.
但是,“with + 復合賓語”結構也可以用作定語.
如：Soon they found themselves walking in a valley with high mountains aroud it.
He lives in a village with a railway behind it.
Harry Potter is a boy with a scar on his forehead.