It was from him，his chemistry teacher，that Paul learned to watch carefully in class.

4.被强调成分是作主语的代词，用主格，是作宾语的代词，用宾格

It was he that helped me yesterday. It was me that he helped yesterday.

5.被强调部分既包括人又包括物，用that不用who

lt was the things and people that they remembered that they were talking about.

三、区分定语从句和强调句型某些定语从句和强调句型形式差不多，容易混淆。如果去掉it is/was ...that句子仍然通顺成立，则为强调句型，不成立不通顺，则为定语从句。

E.g. It was three years ago that he went to American for a further study去掉It was that句子为Three years ago he went to America for a further study.句子通顺，意思完整，那么，这就是一个强调句型。

上文是六年级英语强调句的用法，希望文章对您有所帮助!