强调句的否定转移

就是那个not until的知识点，前辈们能不能讲一讲，举个例什么的理一理。

然后强调句方面一个是基本句型然后特殊疑问句的强调一个原因状语从句的强调，还有哪些地方容易错要注意的么？
求指点……

强调句型主要是可以强调句子的主语，宾语，和状语
强调句基本结构是It is /was + 被强调部分+ that + 其他部分
1.I met him in the street yesterday .可以变为下面强调句型
It was I who /that met him in the street yesterday.（ 强调主语）
It was him whom / that I met in the street yesterday.（ 强调宾语）
It was in the street that I met him yesterday .（ 强调地点状语）
It was yesterday that I met him in the street （强调时间状语）
2. what are you looking for ? 特殊疑问句强调特殊疑问词可以变为
What is it that you are looking for?（ 强调特殊疑问词,始终把特殊疑问词放句首)
3 . He did not come to school because he was ill .
He didn't go to school until he recovered.状语从句的强调句
It was because he was ill that he did not come to school .(强调原因状语从句）
It was not until he recovered that he went to school(强调时间状语从句not until句式 .not until句型中 中把主句中的not和 until放到一起进行强调）