1、否定词+比较级表示最高级含义，可表示强调，例如I couldn't agree with you any more. There is no uglier face like that. Nothing is more difficult than that
3、在上述句型中it没有词汇意义只是引出被强调的成分，如果被强调的成分是表示人的词，用who或that来连接都可以，如果是其他成分一律用that来连接
5、被强调成分是作主语的代词用主格，用作宾语的代词用宾格，例如it was he that helped me yesterday/ it was me that he helped yesterday
