一般正常情况来说，一个句子中的主语和谓语动词往往紧挨在一起，这也是符合大多数的句子结构，同学们最熟悉的主谓或者主谓宾结构。But, 出现重点了，长难句中，往往会“牛郎织女隔河对望”，就是会把主语和谓语动词这对情侣分离开来，请看下面这两个句子结构：
示例1： Prior to 1815, western farmers (who did not live on navigable waterways) were connected to them only by dirt roads and mountain trails.
示例2：The process (perceived by these anthropologists )may be summarized briefly.
对于这种类型的句子结构，童靴们是不是相当熟悉这个套路呢。示例1中，定语从句从中作梗，拆分了主谓。示例2中，过去分词短语拆分了主谓。
那为何我们一定要能快速识别这个套路，对于我们理解句子又有什么帮助呢?这次我们主要分析第二种情况，因为这个比较难以区分，对童靴造成的困扰更大些。以示例2来说：The process perceived by these anthropologists may be summarized briefly.一不小心，主干是这样理解的：The process perceived这也是大多数心大的童靴常犯的问题，看到主语后面紧挨着一个动词，就想当然认为是谓语动词，万事大吉，从而不会继续往后看看这个句子后面是否还有动词。
错误理解：这个过程感知，通过这些人类学家，可能被简短地总结。
正确理解：人类学家感知(体会)的这个过程可能被简短地总结
*总结：句子结构都分析不对，往往意思就会偏差很多。说白了，会影响句子意思准确理解。所以，第一步句子结构得分析正确。
我们再来看这个句子，很明显这个句子有两个动词，一是perceived，二是may be summarized，那么问题就来了，究竟哪个是谓语动词，哪一个是修饰了。判断的方法有多种，根据语法常识，may be summarized是情态动词+实意动词的结构，孩子们还没有接触过这种后置修饰的套路吧。一般来说，情态动词+实意动词，动词原形，动词三单形式，动词有语态变化的，都是常见的谓语动词的形式。但今天，包老湿来个小小的非常实用的tip,从句子结构入手，帮助同学们快速识别过去分词短语后置修饰这个套路，从而和谓语动词区分开来。过去分词短语后置修饰常见结构：done+by/from+n, 介词以by/from居多。我们再把示例2的句子拿出来，The process perceived by these anthropologists may be summarized briefly.眼尖的孩子发现了，perceived by these anthropologists就是done+by+n这种结构。所以这个句子结构是：The process (perceived by these anthropologists )may be summarized briefly.
我们再来看几个句子：
示例3：The gradual drying of the soil caused by its diminished ability results in the further loss of vegetation.
分析：动词caused和results in，其中动词caused是caused by its diminished ability，满足done+by+n这种结构，我们得出这个句子结构，The gradual drying of the soil( caused by its diminished ability) results in the further loss of vegetation.
示例4：At the same time, operators of the first printing presses run by steam rather than by hand found it possible to produce a thousand pages in an hour rather than thirty.
分析：动词run和found，其中动词run是run by steam，满足done+by+n这种结构，得出这个句子结构，At the same time, operators of the first printing presses (run by steam rather than by hand) found it possible to produce a thousand pages in an hour rather than thirty.
示例5：Unfortunately, the cost of water obtained through any of these schemes would increase pumping costs at least tenfold, making the cost of irrigated agricultural products from the region uncompetitive on the national and international markets.
分析：动词obtained和would increase，其中动词obtained是obtained through any of these schemes，满足done+by+n这种结构，不过把介词by换成了through，结构还是一样的。得出这个句子结构，Unfortunately, the cost of water (obtained through any of these schemes )would increase pumping costs at least tenfold, making the cost of irrigated agricultural products from the region uncompetitive on the national and international markets.
最后我们来看一下过去分词短语后置修饰常见结构done+by/from+n的原理，举非常简单的两个句子，相信大家能轻松理解。
1. The lecture (given by Professor Zhang) is about environment protection.
2. The lecture (which was given by Professor Zhang) is about the environment protection.
过去分词或过去分词短语放在名词后面作后置修饰，其功能相当于一个定语从句，并不是做谓语动词哦。