易错点一：混淆强调句与定语从句
It was in the small house ________ was built with stones by his father ________ he spent his childhood.
A. which, that B. that, which C. which, which D. that, where
答案选A，填对此句的关键是要弄清第二空必须填 that，因为这是一个强调句，被强调部分为 in the small house (以及修饰它的定语从句 which was built with stones by his father)。又如：
It was the boy ________ had been in prison ________ stole the money.
A. who, where B. that, how C. who, that D. that, which
此题答案选C，全句为强调句，被强调成分是 the boy (以及修饰它的定语从句who had been in prison)。
易错点一：混淆强调句与状语从句
It’s more than half a century ________ the People’s Republic of China was liberated.
A. when B. that C. since D. after
有的考生一见到句首的 it’s，再一看选项中的that，就马上联想到It is...that... 这样的强调句型，并认为被强调的成分是时间状语 more than half a century，从而毫不犹豫地选择了B。按照以上分析，假若这是强调句，那么若将此句还原为非强调句就应该是The People’s Republic of China was liberated (for) more than half a century. 很显然, 句中的 more than half a century 是一段时间，然而它修饰的谓语动词 (was) liberated 却是一个终止性动词，按此意思则是说“解放中华人民共和国”这一动作一直持续了半个多世纪，这显然是荒唐的。其实，此题应选C，属于“It is＋一段时间＋since 从句”句型，句意为“自中华人民共和国解放以来, 时间已过去半个多世纪”。此句的主句谓语也可以用现在完成时态(has been)，但在口语中一般多用一般现在时代替。
易错点三：混淆强调句与主语从句
It is the Forbidden City that we are going to visit. = We are going to visit the Forbidden City. 我们要去紫禁城。
It is true that we are going to visit the Forbidden City. = That we are going to visit the Forbidden City. (It为形式主语, that引导的从句为真正的主语。)
注：强调句型的一个显著特点就是，若去掉强调句型的结构词 it is / was 和 that / who，句子结构依然完整，若是其他句型，则不行。
易错点四：被复杂的被强调成分所迷惑
It was what he meant rather than what he said ________ annoyed me.
A. which B. as C. what D. that
许多同学对此题的结构分析感到无从下手。其实，此题为一个强调句型，空格处应填 that (即选D)，被强调成分为 what he meant rather than what he said。句意为“让我生气的不是他说的话，而是他话中的意思”。请再看几例：
1. It was his nervousness in the interview ________ probably lost him the job.
A. which B. since C. that D. what
答案选C，为强调句型，被强调成分为 his nervousness in the interview，句意为“很可能是面试时表现出紧张，使他失去了这份工作”。
2. It is the ability to do the job ________ matters not where you come from or what you are.
A. one B. that C. what D. it
答案选B，为强调句型，被强调成分为 the ability to do the job，句意为“重要的是你做工作的能力，而不是你来自何地或你是从事什么工作的”。