Traditionally, the first firm to commercialize a new technology has benefited from the unique opportunity to shape product definitions, forcing followers to adapt to a standard or invest in an unproven alternative.
该句的基本结构为：…，the first firm to… has benefited from the unique opportunity to…，…
一个完整的句子中主语和谓语是必不可少的，常见的错误是出现三种不完整的句子结构。一是缺少主句；二是缺少主语；三是缺少谓语，包括主句缺谓语和从句缺谓语两种情况。特别是what从句不能缺少谓语。例如：the necessity of what kind of military action in order to do…是错误的，而正确的表达方式为what military action is necessary to do…
then, also, therefore, however (THAT) 等副词不能代替and起连词的作用。then在并列结构的用法为：do A and then do B; doing A and then doing B; suspect sb. of having done A and then doing B，上述结构中and不能省略。
介词不能代替连词
任何介词都不能用作连词引导从句，即介词后面不能加主谓结构。例如：High levels of fertilizer and pesticides, needed by farmers try to produce high yields of the same crop year after year, pollute water supplies. 句中的介词by 应该为连词when。
6. 介词后面一般只能接疑问词引导的宾语从句，不能接that引导的宾语从句。但有三个例外：but that = except that，in that (= because)。
7. 宾语从句后面跟有补语，通常使用形式宾语it代替，如：。。。make it clear that…。
表语从句
1. 表语从句位于主句系动词之后，可分为两类：be + that 型从句和 be + 疑问词型从句。
2. be + that 型从句；
例如：The result is that water supplies are being taken from farmers to meet the needs of a growing unban population.
3. be + 疑问词型从句；
例如：What is in question is whether an improvement in nutrition was the main reason for the decline of infectious diseases before the late nineteenth century.
4. 表语从句使用陈述语序；
5. 主句主语是reason时，表语从句要用that引导，不可用because。但reasons作主语时，表语要用名词短语并列，例如：The most common reasons for… are 名词短语1，名词短语2 and 名词短语3。作者: myice 时间: 2010-7-30 16:49
特殊结构
强调结构
1. It is/was + 强调对象 + that / who
2. It was not until … that …
3. 强调动词： do / did / does + verb.
4. if any：做插入成分，强调名词短语，表示如果有的话。
5. many + 名词短语, if not most, verb.
例如：Although Ms. Bakara had previously emphasized that she could not speak for other Black people, she ventured to do so on this one occasion because she firmly believed that many minority people, if not most, would agree with her.
6. … as … as… , if not more so
例如: The use of chemical pesticides in this country is as extensive as it was ten years ago if not more so.
倒装结构
1. so / such … that 中so 短语和such短语谓语句首时，需要部分倒装。
2. 否定词或者短语位于句首时，部分倒装：never; no longer; rarely; hardly; few; little; not until;
2. 省略往往是为了避免重复。可以承接前面的内容省略（承前省略），也可以承接后文的内容省略（后指省略）。例如：He is not only a teacher of English, but also of Chinese. （of 前省略了 a teacher）
3. 省略的部分要能够“还原”，还原后语法上要求结构对应，逻辑关系正确。
4. 并列结构中的省略：
1) 省略相同的主语，宾语，系动词，助动词，情态动词：sb. do…and (sb.) do…; sb. do (sth.) and do sth.; sth. be A and (be) B; be doing …and doing…; be done and done; have done… and done…; will do… and do…; must/ would/ should/ can/ should/ may do… and do…
2) 两个句子并列，第一个句子有be动词或者become动词，则第二句中的be动词或者become动词可以省略，同时，一些重复的名词或形容词也可以省略。例如：Once the economic and social usefulness of the motor car was demonstrated and its superiority to the horse proved, … (proved 前省略了was) 但实意动词不能省略；
5. be 动词或 being 常倾向于省略：
be known as being sth. (省去 being)；n. , being sth. (省去 being)
6. 习惯性省略：as needed; as planed; as required; as scheduled; whenever necessary/ needed/ possible; wherever necessary/ needed/ possible; than ever; than before; than ever before; than usual; than expected; than predicted; than estimated; than anticipated.
1) 形式一：否定词 + 否定词缀，如：not incapable, not unlike…, nothing impossible, never dissatisfied。
2) 形式二： 否定词 + 含有否定意义的词语，如：there is no doubt that…; Man cannot live without water。
3) 形式三：否定词 + 否定词或否定句，如：No one should do nothing to society. / He is nothing if not diligent.
4. 意义上的否定
英语中有些词和短语在意义上表示否定，如：little, few, seldom, scarcely, hardly, too…to, rather than, fail/failure to do…, in the absence of, no more…than…(与…同样不), no amount of(怎么…也不…), no longer, by no means, in no way, cannot…too。
