總是聽到“概括大意(main idea)”。而且基本“套路”就是那幾句話：段首段尾句、文章開頭和標題。

可是為什么我總是找不到?總是會找錯?

為什么我覺得自己選的沒錯，老師卻說我做的不對?

如何防止概括時出現這三種錯誤?

跑不到：概括不全;

跑過了：過于籠統;

跑偏了：題不對文。

下面五條建議，不僅僅是“干貨”。

Read the first and last sentences of the paragraph (or the first and last paragraphs of the article). Authors often state the main idea near the beginning or end of a paragraph. Look for a sentence that states the main idea. This is the stated main idea or topic sentence.

段落的第一句、或者最后一句;如果是整篇文章，則看第一段或者最后一段。其實文章如果有配圖或者小標題的情況下，就更好找了。

Pay attention to any idea that is repeated in different ways. If an author returns to the same thought in several different sentences (or paragraphs), that idea is the main or central thought under discussion.

閱讀測試那種“四選一”的題目，如果只有一個選項在句子中能找到完全一樣的原話，那么——呵呵你想多了，這不能說明什么!

正確的做法，還是內容：作者是否多次、用不同的句子、表達了同一個思想主題，而且還是在文章的不同位置，那基本就是他/她想告訴你的主旨。

Look for reversal transitions at the beginning of sentences. These signal that the author is going to modify the previous idea. When a reversal transition opens the second sentence of aparagraph, there’s a good chance that the second sentence is the topic sentence and a stated main idea. Some samples of reversal transitions:

作者常常在文章開始，來個“先抑后揚”、先說普遍再說特殊，這時，句群會出現一種反轉關系，那么這些反轉關系的標記詞很重要，因為在其后，那個句子很可能就是本文或本段的主旨了。

這些詞語包括：

But

Nevertheless

Still

Conversely

Nonetheless

Unfortunately

Evenso

On the contrary

Whenin fact

However

Onthe other hand

Yet

Incontrast

Regardless

At times the main idea will not be stated directly. This is called an implied main idea. Read all of the specific statements, not just the ones that open the paragraphs. Think of ageneral statement that could sum up the specifics as effectively as any stated topic sentence. As there will not be a topic sentence, you will have to write one.The main idea you write must be a complete sentence that contains a subject and a verb and expresses a complete thought.

更多時候，作者不會很明確地說出主旨，而是“暗示”。那么就需要認真讀第一段所有句子，試著用自己的話把它寫出來。這個句子必須是完整的、包括主語和謂語的句子。

之前我們一直強調“三字經”，即用“一句話、三元素”來概括段落或整篇文章：(1)誰：文章講的是何人、何物?(2)做什么：這個人、物做了什么?(3)怎么做：是怎么做的?這樣可以防止概括過于籠統、或過于具體。

Once you feel sure that you have found the main idea, test it. Ask yourself if the sentence could act as a summary of the other sentences in the paragraph. Do the examples, reasons, and facts included in the reading explain or give evidence supporting the main idea you have in mind? If they do, then you are right on target. If they don’t, you may want to revise your main idea.

一旦你寫出了、或者選出了那個main idea的句子，要試著“證明”一下：文章中的例子、事實、原因……是否能共同指向你這個主旨句，即：都在證明、或者解釋它。

一般我們容易犯的錯誤就是這個主旨句太“寬”或太“窄”。太寬，就是說它可能涵蓋了很多本文并沒有涉及的細節，那么它就可能off the point(跑題);太窄，則是它僅僅涵蓋到文中部分細節。所以心里要始終問這個問題：What do all major details share in common?

總結一下：以下位置可能提示主旨：

文中直接呈現為標題、首尾句;

用不同的句子表達相同的主題;

轉折詞(如but)后面的句子;

用“主謂狀”一句話，說出文中所有事實、細節、原因等的共性。