有时一个本来很简单的句子，由于表达的需要，在其中置入一个插入成分，或将某些成分从正常位置调入一个在同学们看来属“非正常”的位置(如宾语从句前置等)，则很有可能给同学们的理解带来困难（尤其是阅读能力不是很好的同学会更感困难）。假若命题人就此命题，那就更麻烦了。请看以下几个典型实例：
1. Don’t you know, my dear friend, _________ it is you that she loves?
A. who B. which C. that D. what
【分析】此题容易误选 A或B，选 A 者认为这是指人的，故用 who；选B者认为这是非限制性定语从句，两者都是误认为这是定语从句(注意没有先行词)，其实此题应选C，它引导的是一个宾语从句，只是被其中的插入语 my dear friend 隔开罢了。其实此句也可说成 My dear friend, don’t you know that it is you that she loves? 又如：
I think, though I could be mistaken, _________ he liked me.
A. who B. which C. that D. what
答案选 C，句子可改写为 I think that he liked me, though I could be mistaken. 即 that he liked me 是动词 think 之宾语从句。
2. He told me the news, believe it or not, _________ he had earned $1 000 in a single day.
A. that B. which C. as D. because
【分析】此题容易误选 B，误认为这是非限制性定语从句。其实此题应选 A，that 引导的是一个用以修饰名词 the news 的同位语从句。不少同学之所以误选B，正是 believe it or not（信不信由你）这个插入成分惹的祸。
3. John plays football _________, if not better than, David.
A. as well B. as well as C. so well D. so well as
此句的正常结构是这样的：John plays football as well as David, if he doesn’t play football better than David. 由于命题者将其后的状语从句移至句中，且将其省略成 if not better than，不少学生(尤其是一些阅读能力较差的学生)对这个句子的分析感到无从下手，从而导致误选。此题正确答案应为 B。
【分析】此题应选B。容易误选A。这是一个省略句, 其中的 if not better than＝if he doesn't play football better than。全句意为：吉姆踢足球如果不是比迈克踢得更好, 至少也是一样好。请做以下类似试题 (答案均选D)：
(1) Her pronunciation is _________, if not better than, her teacher's.
A. as well B. as well as C. as good D. as good as
(2) This bridge is _________, if not stronger than, that one.
A. so strong B. as strong C. so strong as D. as strong as
(3) He has been to Paris_________, if not more than, ten times.
A. so much B. so many C. so much D. as many as
4. Dorothy was always speaking highly of her role in the play, _________, of course, made the others unhappy.
A. who B. which C. this D. what
许多学生认为此题句子结构比较混乱，逗号太多，难于理清头绪。请同学们先看下面一句：Dorothy was always speaking highly of her role in the play, _________ made the others unhappy. 一般同学都知道此题应填关系代词 which，用以引导一个非限制性的定语从句。事实上，上面一题就是根据此题演变出来，只不过在 which 与 made 之间插入了一个 of course。所以上面一题应选B。又如：
(1) The meeting was put off, _________, of course, was exactly what we wanted.
A. who B. which C. this D. what
(2) He was very fond of speaking French, _________, indeed, he spoke well.
A. who B. which C. this D. what
以上两题答案均选B，which 引导的为非限制性定语从句，其后的 of course 和 indeed 为插入成分。
5. Would you care to wait here, sir, _________ the manager can see you?
A. when B. since C. until D. while
如果撇开句中的插入成分 sir，句子则为 Would you care to wait here _________ the manager can see you? 根据句意，显然应填 until。
6. He believes in himself, _________, in my opinion, is of the most important.
A. that B. which C. what D. as
【分析】此题应选B，句中的 in my opinion 为插入成分，如果将其撇开，句子则为 He believes in himself, _________ is of the most important. 空格处显然应填 which，用以引导一个非限制性的定语从句，句意为“他很自信，我认为这是最重要的”。
7. By the window sits his wife, who, dressed in black, _________ like my aunt.
A. look B. looking C. looked D. looks
答案选D，但B和C可能被误选。此句的基本结构是 His wife sits by the window，由于句子主语 his wife 带有自己较复杂的修饰语，所以采用了倒装语序(By the window sits his wife…)。另一方面，由于 his wife 后接的定语从句 who looks like my aunt中插入了一个过去分词短语(dressed in black)，所以有的同学没有意识到 looks 是定语从句的谓语，而考虑到选 looked 与前面的过去分词 dressed 保持一致。
8. The first part, it seems, _________ better written than the other parts.
A. being B. to be C. is D. 不填
答案选C，其中的 it seems 为插入成分，句子的基本结构是 The first part is better written than the other parts. 请看以下类例：
(1) The cross-talk, I think, _________ both interesting and instructive.
A. being B. to be C. is D. 不填
(2) Life, in his opinion, _________ nothing but a dream.
A. being B. to be C. is D. 不填
(3) That dictionary, you know, _________ meant chiefly for Chinese students.
A. being B. to be C. is D. 不填
(4) The audience, more than one thousand of them, _________ up and applauded the singer.
A. standing B. to stand C. stood D. to be standing
答案均选C，其中的 I think, in his opinion, you know, more than one thousand of them 等均为插入语，做题时可以将其撇开不管。