it is that 强调句用法如下：
当需要强调句中的主语，宾语和状语时，常用强调句：it is/was+ 被强调的部分 ＋that/who.
He bought three books in the bookstore yesterday.
强调主语：
It was he that/who bought three books in the bookstore yesterday.
强调宾语：
It was three books that he bought in the bookstore yesterday.
强调状语：
It was in the bookstore that he bought three books yesterday.
扩展资料
1、陈述句的强调句型
It is/ was + 被强调部分（通常是主语、宾语或状语）+ that/ who（当强调主语且主语指人）+ 其他部分。
例如：It was yesterday that he met Li Ping. 昨天他遇到了李平。
2、 一般疑问句的强调句型
It is/ was + 被强调部分（通常是主语、宾语或状语）+ that/ who（当强调主语且主语指人）+ 其他部分。同上，只是把is/ was提到it前面。
例如：Was it yesterday that he met Li Ping? 昨天他遇到了李萍吗？
3、特殊疑问句的强调句型
被强调部分（通常是疑问代词或疑问副词）+ is/ was + it + that/ who + 其他部分？
例如：When and where was it that you were born? 你何时何地出生？
4、not … until … 句型的强调句
句型为：It is/ was not until + 被强调部分 + that + 其他部分；此句型只用until，不用till。但如果不是强调句型，till, until可通用；因为句型中It is/ was not 已经是否定句了，that后面的.从句要用肯定句，切勿再用否定句了。
普通句：He didn't go to bed until/ till his wife came back. 强调句：It was not until his wife came back that he went to bed.
5、谓语动词的强调
It is/ was ... that ... 结构不能强调谓语，如果需要强调谓语时，用助动词do/ does或did.
例如：Do sit down. 务必请坐。Do be careful when you cross the street. 过马路时，务必（千万）要小心啊！
此种强调只用do/ does和did，没有别的形式；过去时用did，后面的谓语动词用原形。
"it is that" 是一个引导同位语从句的结构，用于进一步解释或说明先行词。同位语从句是一个解释或说明先行词的从句，它通常跟在先行词后面，用于进一步解释或说明先行词。"it is that" 引导的同位语从句一般放在先行词后面，用于进一步解释或说明先行词。例如：
My favorite food, it is that which reminds me of home.（我最喜欢的食物，正是那种让我想起家乡的食物。）
在这个例子中，“it is that which reminds me of home” 是一个同位语从句，解释了先行词“my favorite food”的具体内容。
"it is that" 也可以用作引导主语从句的结构。在这种情况下，"it" 是形式主语，而主语从句则是真正的主语。例如：
It is that she left without saying goodbye that hurts me the most.（她不告而别，正是这点让我最受伤。）
在这个例子中，“that she left without saying goodbye” 是一个主语从句，而 "it" 则是形式主语，用于引导主语从句。