强调句型是英语语法考试经常涉及的一个考点，这类考题主要涉及以下几个方面：
一是考查强调句型的基本结构，即“It is + 被强调成分 + that / who +其他部分”;
二是考查强调句的疑问句形式，如强调句的一般疑问句形式“Is it + 被强调成分 + that / who +其他部分”以及特殊疑问句形式“疑问词+is it that+其他部分”;
三是考查not…until…的强调形式“It was not until….that….”。如：
It was from Betty that he first heard the news. 这消息他最早是从贝蒂那里听到的。
Was it you who broke the window? 窗子是你打破的吗?
It was not until the rain stopped that they started. 直到雨停他们才出发。
How long ago is it that you last saw her? 你上次看见她是多久以前的事?
A.句型强调
英语中最常见的强调手段，也是我们必须要掌握的方法就是句型强调，即：强调句型。It is / was + 被强调的部分 + that (who)…如：
(1) It was in the room that Li Lei was born. 李蕾出生就在这间房子。
(2) It is Wei Fang who has broken the record. 就是魏方打破了纪录。
B.在使用强调句型时须注意的几个问题：
(A) 原句子是现在时或将来时，强调句用It is + 被强调的部分 + that (who)…; 若原句子是过去时，强调句用：It was + 被强调的部分 + that (who)…
(1) Li Lei’s father will work in America. —It is in America that Li Lei’s father will work. 李蕾的父亲的工作将就在美国。
(2) I studied at this school a few years ago. —It was at this school that I studied a few years ago. 几年前我就在这所学校读书。
(B) 即使被强调的部分是复数，It后面始终用单数形式。如(from www.yygrammar.com)
(1) Tom and Lucy gave us much help. —It was Tom and Lucy that gave us much help. 正是汤姆和露西给了我们很多的帮助。
(2) I saw swans in the lake yesterday. —It was swans that I saw in the lake yesterday. 昨天我看到在湖里的就是天鹅。
(C) 强调人时，可用who 代替that, 但若强调时间、地点、原因、方式时，不能用when, where, why, how代替 that。如：
(1) It is our teacher who / that helps us make great progress. 正是我们的老师帮助我们取得了很大的进步。
(2) It is by bus that I go to school every day. 每天我就是乘公共汽车上学。
(D) 在强调not…until结构中的时间状语时，应将not移到until前，再将not until部分移到被强调的位置。如：
I didn’t go to bed until twelve o’clock last night. — It was not until twelve o’clock last night that I went to bed. 昨天晚上我一直到十二点才睡。
(E) 强调一般疑问句中的某一成分时，将强调句中的主句用一般疑问语序。如：
(1) Do you like English?—It is English that you like? 英语就是你喜欢的吗?
(2) Will you go to London?—It is London that you will go to? 你要去的就是伦敦吗?
(F)特殊疑问句中只有疑问词可以被强调。句型为：特殊疑问词+be + it that+…? 如：
(1) What made him so angry?—What is it that made him so angry? 是什么东西使他如此生气?
(2) Why did she cry?—Why was it that she cried? 是什么原因使他哭了起来?
(G) 强调主语时，who 或that后面的谓语形式须与被强调的主语保持一致。如：
(1) Lily speaks Chinese very well. —It is Lily who / that speaks Chinese very well. 李丽的汉语讲得很好。
(2) Children like stories. —It is Children that like stories. 孩子们喜欢故事。
(H) 强调句中的be前可用表推测的情态动词：must, can, may等。如：
(1) It must be Piney that sent us this present. 肯定是Piney 给我们寄来了这件礼物。
(2) How can it be that he didn’t pass the exams. 他考试没有通过怎么可能呢?
(I) 强调句型不用于强调谓语、表语、since, as等引导的原因状语从句。如：
He is better today since he can walk around without my help. 就不能有下列强调形式：
It is better today that he is today since he can walk around without my help. (错)
It is since he can walk around without my help that he is better today. (错)
From:https://www.zgghmh.com/CET-6/20007553.asp