托福阅读的长难句是其标志性难点之一，也是很多同学看不懂看不快阅读文章的罪魁祸首。其实长难句只是一个统称，其中包含了多种复杂的句式结构。下面小编就为大家重点分析其中的倒装句式，一起来看。
1. 虚拟条件句谓语含 were, had, 或 should如果虚拟条件句的谓语部分含有 were, had, 或 should, 可以把他们放到句首 , 省略连词 if, 变成倒装句。
真题例句 1：In contrast, should another ice age occur, sea level would drop drastically. ( TPO15-3 Glacier Formation )
解析：对于这种倒装句的处理是：一步，把 if 还原 ; 第二部，理解句子。因此 if 还原之后该句变成："In contrast, if another ice age should occur, sea level would drop drastically." 由 if 引导的从句 "should occur" 的使用可知，该句是对将来的虚拟。意思为：对比之下，如果再次发生冰川世纪，海平面将会大大下降
真题例句 2：Their significance may have remained clear had the Chinese not come under foreign influence. ( TPO10-1 Chinese Pottery 11 题 )
解析：该句是把条件从句放在了句子后面，if 还原之后变成："Their significance may have remained clear if the Chinese had not come under foreign influence." 由 "had not come" 的使用可知该句是对过去的虚拟，意思为：如果没有受到外国的影响，它们的重要性可能保持清晰。"
2. 否定意义形式词或词组位于句首
never 等具有否定意义或否定形式的词或词组位于句首时用倒装。
常见词或词组有： not, never, rarely, little, hardly, seldom, on no account, by no means, neither, nor … 因此，对于倒装句 " … not until the second of December did they kill their first elk." 来说，一步先把句子变成正常语序，即把 not 的位置还原，第二步再理解句子。那么这个句子就变成 " … they did not kill their first elk until the second of December。" "not … until" 表示 " 直到……才 "，因此句子意思为：他们直到第二年的十二月才杀死了一批麋鹿。
3. "only 状语 " 位于句首当 "only 状语 " 位于句首时表强调使用倒装。
真题例句：Only recently have investigators considered using these plants to clean up soil and waste sites … ( TPO5-1 Minerals and Plants )
解析：该句是 only recently ( 时间状语 ) 位于句首引起的倒装，因此该句变成正常语序为："Investigators have only recently considered using these plants to clean up soil and waste sites … ", 意思为：研究人员才考虑使用这些植物清理土壤和垃圾场。
4. "so/such … that" 结构中的 so 或 such 位于句首
为加强语气 "so/such … that" 结构中的 so 或 such 位于句首时用倒装。
真题例句："So admired were these pieces that they encouraged the development of earthenware made in imitation of porcelain and instigated research into the method of their manufacture. ( TPO10-1 Chinese Pottery )
5. 主语较长需平衡或强调句子主语较长，为使句子平衡或强调，倒装表语或状语。
这种倒装句通常是介词短语、形容词 ( 短语 ) 和分词 ( 短语 ) 位于句首。

如： By his sides is his wife who is very elegant and beautiful. ( 在他旁边是他美丽优雅的妻子 )
Green are the clouds in the sky and faded are leaves on the ground. ( 碧云天，黄叶地 )
Sitting in the class are students who come from all across the China. ( 坐在教室里的学生来自各地 )
真题例句：Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans. ( OG The Origins of Cetaceans )
解析：该句的主语是 "fossils clearly intermediate, or transitional, between land mammals and cetaceans." 其中 "intermediate, or transitional, between land mammals and cetaceans" ( 哺乳动物和海洋鲸鱼之间过渡性 ) 是 "fossils" 的定语。由于该句主语过长，为了使句子平衡，把表语 "Missing until recently" 置于句首引起倒装句。该句变成正常语序为："Fossils clearly intermediate, or transitional, between land mammals and cetaceans were missing until recently." 意思为 " 哺乳动物和海洋鲸鱼之间过渡性的化石现在找到了。"
以上就是托福阅读长难句中 5 大类倒装句的结构实例分析，缺乏长难句基础的同学赶紧来学习了解一下吧。