託福閱讀中的長難句非常影響考生理解題意，所以，要想得到高分，就一定要攻克長難句這個堡壘。知己知彼百戰百勝，首先，我們需要了解長難句的型別，然後再分析句子結構，找準長難句的中心詞彙。 除了詞彙量較大以外，句子結構複雜也是託福閱讀的障礙之一。面對難句，必須迅速把握其主幹和重點，因為考試時涉及答案的主要是句子的主幹和重點，對於句子簡化題(sentence simplification)尤其如此。要把握難句的主幹和重點，首先要弄清它們的型別。簡而言之，託福中的難句主要包括下列型別：
1.定語(包含後置定語與定語從句)
2.同位語
3.並列結構
引導的各種從句
5.插入結構
6.獨立主格
7.倒裝句
8.強調句
9.虛擬語氣
對於不同型別的'難句，把握主幹的方法也不一樣。以倒裝句為例，主要有下列情況：
1.方位副詞放在句首
Herein lay the beginning of what ultimately turned from ignorance to denial of the value of nutritional therapies in medicine。
2.介詞放在句首
Among the species of seabirds that use the windswept cliffs of the Atlantic coast of Canada in the summer to mate, lay eggs, and rear their young are common murres, Atlantic puffins, black-legged kittiwakes, and northern gannets。
3. 形容詞放在句首
Implicit in it is an aesthetic principle as well: that the medium has certain qualities of beauty and expressiveness with which sculptors must bring own aesthetic sensibilities into harmony。
4.過去分詞放在句首
Accustomed though we are to speaking of the films made before 1927 as silent， the film has never been, in the full sense of the word, silent。
5.現在分詞放在句首
Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans。
句子倒裝的目的主要有兩個：
一是被提前的部分被強調，如上述的第四句：Accustomed though we are to speaking of the films made before 1927 as silent，其中的accustomed按照正常語序應該放在are之後：Though we are accustomed to speaking of the films made before 1927 as silent。之所以將accustomed提前，是為了強調它。二是為了句子的平衡，否則將導致頭重腳輕的效果，如上述的第一句、第三句和第五句。以第五句為例，按照正常語序應該是：Fossils clearly intermediate, or transitional, between land mammals and cetaceans were missing until recently。但是這種句子結構比較糟糕，因為主語及其修飾語過長(從句首直到cetaceans)，而謂語部分were missing until recently較短，容易造成頭重腳輕的效果。第五句將missing提前，避免了這一現象。
託福閱讀中為了考試時能迅速把握句子的主幹，需要進行更多的閱讀和分析，每篇文章都是一次鍛鍊的機會，千萬不可敷衍了事，明白它們的結構和意思，反覆分析，托福考試時就能做到駕輕就熟了。
