在英语语法中，平行（也称为平行结构或平行结构）是在句子的两个或多个部分重复相同的语法形式。

保持平行结构可以帮助你避免语法错误的句子，提高你的写作风格。虽然缺少排比并不总是严格错误的，平行结构的句子更容易阅读，并为你的写作增加平衡感。

并列结构最常用于句子中包含成对或串联的成分。它也适用于学术写作中的标题和提纲。

当两个相似的短语连在一起构成一个句子时，就出现了排比现象。例如:

• Tom plays the piano.

• Tom plays the violin.

• Parallelism = Tom plays the piano and the violin.

这只是一个简单的例子。有许多类型的并行，需要记住的重要一点是，这两种形式必须是相同的。换句话说，如果你有两个并列的动词结构，它们的时态必须相同。例如:

• Peter works hard and plays hard. NOT Peter works hard and play hard.

单字平行结构

前面的两个例子都是单字平行结构。下面是单字平行结构的概述:

名词

• Jack eats fish and chicken.

• Sarah writes poetry and short stories.

动词

• Our neighbors have moved and have sold their house.

• My sister walks or rides her bike to work.

形容词

• he class is not only fun but also helpful.

• She is not only strong but also fast.

副词

• Peter drives quickly and aggressively.

• They work carefully and effectively.

短语平行结构

短语上也可以出现排比现象。这种类型的平行结构可能更难识别，因为句子更复杂。以下是一些例子:

• Having fun is as important as working hard.

• She advised me to get some sleep and take some time off work.

这是短语平行结构。每种类型的结构都包含一个关于需要考虑的要点/问题的注释。

名词短语

• Work is as necessary as play.

• Apples are as good for you as oranges.

注意:名词短语在性质上可以是单数或复数，也可以是非人称的(it或they)。

动词短语

• Work is as necessary as play.

• Apples are as good for you as oranges.

注意:平行结构动词短语中的所有动词都具有相同的词形变化。

副词短语

• As soon as I arrive home, I put on my shoes and go for a run.

• Before she leaves for work, she usually eats breakfast and has a cup of coffee.

注意:一个副词短语是由多个起副词作用的词组成的。在这种情况下，In less than an hour and In time表示某事将要发生。

动名词短语

• He enjoys playing tennis and working out.

• They don't mind waiting and talking while you get ready.

注意:在平行结构中不要把不定式(to do)和动名词(doing)混在一起!

不定式短语

• Jackson hopes to visit his parents and see his old friends when he goes home.

• She advised me to find some new friends and forget about the event.

注意:在平行结构中不要把不定式(to do)和动名词(doing)混在一起!

分词短语

• Discovering her financial losses and not knowing enough about the current market, she decided to stop investing.

• Driving through the German countryside and speaking to the people, Mark began to understand the culture better.

注意:这是一个相当复杂的结构。注意逗号是如何放在介绍句子的并列结构分词短语后面的。

使用平行结构

最后，从句也可以用来构成平行结构。在这种情况下，记住你必须使用完整的从句结构(主语+动词+宾语)，而且两个从句的主语是相同的。这使得两个从句中的动词变位保持不变。

名词子句

• She said that she was having fun but not that she was meeting people.

• Peter felt that he had made an excellent deal and that he had bought a masterpiece.

形容词子句

• She is a woman who is intelligent and, at the same time, who seems distracted.

• This is a product that is easy to use and that is simple to clean.

副词子句

• As he didn't understand and because he refused to try, they let him go.

• Since it was easy to use and because it was cheap, it sold very well.