独立主格结构
状语从句，非谓语动词，独立主格结构都可以做状语。
非谓语动词作状语，其逻辑主语必须和主句主语一致；如果作状语的非谓语动词的逻辑主语与主句主语不一致，刚要非谓语动词前加上其逻辑主语，构成独立主格结构。
He got up early to catch the first bus.
He hurried to the station, only to be told that the train had left.
Absorbed in watching the football match, he didn’t notice Susan come in. Hearing the news, he jumped with joy.
The professor came in, followed by a group of students. 比较：
1 When we see the city from the top of the mountain, we find the city more beautiful. =Seeing the city from the top of the mountain, we find the city more beautiful.
2 When the city is seen from the top of the mountain, the city looks more beautiful. =Seen from the top of the mountain, the city looks more beautiful.
3 When we see the city from the top of the mountain, the city looks more beautiful. =We seeing the city from the top of the mountain, the city looks more beautiful. 独立主格结构的构成： 名词/ 代词 + to do
doing done adj adv prep n
Such an able man to help you，you will surely succeed sooner or later. ( = Since such an able man will help you, you will surely succeed sooner or later.) 有这么能干的人来帮你, 你迟早一定会成功的。
He seating himself at the desk, his mother began to tell him a story. = When he seated himself at the desk, his mother began to tell him a story.他在书桌旁坐好后，他母亲开始给他讲故事。 1名词/ 代词+doing
The boy leading the way, we had no trouble finding the strange cave.
由那个男孩带路，我们没有困难就找到了那奇怪的洞。（相当于一个原因状语从句Because the boy led the way）
Time permitting, we will have a picnic next week. 时间允许的话，我们下星期将进行一次野炊。（相当于一个条件状语从句If time permits)
2名词/ 代词+done
The book written in simple English, English beginners were able to read it. ( = As the book was written in simple English，English beginners were able to read it.) 该书是用简单英语写的，英语初学者也能看懂。
The task completed, he had two months' leave. （=When the task had been completed, he had two months' leave.）任务完成以后，他休了两个月的假。
3名词/ 代词+to do
His mother to come tonight，he is busy preparing the dinner. （= As his mother is to come tonight, he is busy preparing the dinner.） 他母亲今晚要来,他正在忙着准备饭菜。
Many trees flowers and grass to be planted our newly-built school will look even more beautiful. (=If many trees flower , and grass are planted our newly-built school will look even more beautiful.)种上许多的树，花和草后，我们新建的学校将看上去更美。
比较：
动词不定式表示动作没有发生或即将发生，动词-ed形式表示动作已经结束，动词-ing形式往往表示动作正在进行。
The manager looks worried，many things to settle. 经理看上去很着急, 有这么多的事情要处理。（事情还没有处理，而且是由经理本人来处理，用不定式to settle） The food cooked, the boy went to bed. 饭做好了，小孩去睡了。（两个动作有先后，饭已做好，小孩才去睡觉的）
4名词/ 代词+(being)+名词
Ten students entered for the competition, the youngest a boy of 12. 十个学生报名参加了这次竞赛，年纪最小的是个12岁的男孩。
5名词/ 代词+(being)+形容词
He turned to me, his eyes sleepy. = He turned to me, and his eyes were sleepy. 他睡眼惺忪地转向我。
He stood there, his mouth wide open. = He stood there, and his mouth was wide open. 他站在那里，嘴张得大大的。
6名词/ 代词+(being)+副词
School over, we all went home. = School was over, and we all went home. 放学了，我们都回家了。
He sat at his desk, his shoes off. = He sat at his desk and his shoes were off. 他坐在课桌旁，没穿鞋子。
7名词/ 代词+(being)+介词短语
He is standing in front of the blackboard, his back towards us.
The new teacher came in, a smile on her face.新老师面带微笑走了进来。 The teacher came into the classroom，a rule in his hand. 老师走进教室，手里拿着一把直尺。 提示：
在“逻辑主语+介词短语”构成的独立主格结构里，如果名词用单数，可以不用冠词，同时介词短语里的限定词也可省略。
The music teacher stood at the door, violin in hand. 音乐老师站在门口,手里拿着一把小提琴。（= The music teacher stood at the door, a violin in his hand.）
注意：
1 there be 的独立主格结构为 there being
2 独立主格结构中的being在下列两种情况下一般不能省略，①在“There being + 名词”结构中，②在逻辑主语是代词的情况下。
There being no bus, we had to walk home. 由于没有公共汽车，我们只好走回家。 It being Sunday, all the offices are closed. 因为是星期日，所有办公室都关门。 二、独立主格结构的句法功能
独立主格结构在句子中作状语，表示时间、原因、条件和伴随等情况。 1. 作时间状语
School over, the students went home. 放学后，学生们都回家了。 The ceremony ended, the games began. 仪式结束后，比赛开始了。 2. 作条件状语
It being fine tomorrow, we’ll go boating. 如果明天天气好的话，我们就去划船。 Li Lei coming, it is not necessary to ask Wu Dong. 如果李蕾来的话，就没有必要叫吴东了。 3. 作原因状语
The meeting put off, we needn’t hurry. 由于会议推迟了，我们就没有必要匆忙了。 Mr. Li being ill, Miss Yang will give us this lesson instead. 李老师病了，杨老师将代他来给我们上这堂课。 4. 作伴随状语
Mr. Li comes here, with a book in his hand. 李先生手里拿着书过来了。 A smile on her face, she asked what she could do for us.