你的句型在哪里?so...that是复合句.too..to是简单句.如:heissoyoungthathecan'tgotoschool.=heistooyoungtogotoschool.这是同主语转换.thestoneissoheavythattheboycan'tcarryit=thestoneistooheavyfortheboytocarry.这是主语不同的转换.
这样的句型还可以用enoughto转换.如第一个句子theboyisnotoldenoughtogotoschoo.这也是简单句.再如:theboyissooldthathecangotoschool.=theboyisoldenoughtogotoschool.认真分析这几个转换类型,希望对你有所帮助.