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。