这篇文章使用的存现结构出现了两个文体写作毛病——语句冗长，弱性动词过多。以"it is," "it was," "there is" or "there are"开头的句子大部分(不是全部)都是存现结构。整体上说，一个存现结构一般都以没有实际意义的"there" 或"it"开头(有时也叫形式主语)。在存现结构中，"there"或"it"不是充当主语的作用。也就是说，它没有先行词。词没有任何意思，只是一个占据空间的单词。这个无意义的主语后面会跟着"to be"动词组，比如"it seems"词组后面会跟着谓语。

这样结构的句子会使句子冗长并且无效率，来看看对比效果：

• It was the final goal of the game that determined the state championship.

• There were two students at my summer camp who had severe psychological problems.

• It is Saturday when I get to spend time at the animal shelter.

这三句话都很冗长，去掉那些不必要的部分句子就精练了。

• The final goal of the game determined the state championship.

• Two students at my summer camp had severe psychological problems.

• On Saturday I get to spend time at the animal shelter.

注意不是所有的"it is" "it was" "there is" 或 "there are"都是存现结构。如果"it" 或"there"指代一个真正的名词，就不是存现结构。例如：

• I have always loved music. It is one of the most important parts of my life.

In this case, the word "it" in the second sentence refers to "music." No expletive construction exists.

这种情况下，"it"指代的是"music"，就不是存现结构。

上面的例文，很好改成以下："My parents made a simple rule that got me interested in the trumpet: no television or computer time until I had practiced for half an hour. This rule often angered me, but when I look back I know my parents knew best. Today I'll always pick up my trumpet before the television remote."

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