在同义句改写中情态动词+动词原形可以和to do替换吗?如果不是又是什么用法呢?如：

题目

在同义句改写中情态动词+动词原形可以和to do替换吗?如果不是又是什么用法呢?如：
I don't know how I can get to the TV factory .
= I don't know how to get to the TV factory .
Mike hopes he can visit the Great Wall one day .
= Mike hopes to visit the Great Wall one day .

答案

I don't know how I can get to the TV factory .
= I don't know how to get to the TV factory .
Mike hopes he can visit the Great Wall one day .
= Mike hopes to visit the Great Wall one day .
这样的替换毫无疑问是正确的!但是,要注意理解这两点：
①【两个句子本质不同】：原始句是【复合句】；替换句是【简单句】
【I 主语】【don't know谓语】【 how I can get to the TV factory .宾语从句】
=【 I】【 don't know】【 how to get to the TV factory .“疑问词+不定式”构成不定式短语】.
②把握【替换的条件】：
在【主句主语和从句主语相同时】,此类宾语从句才可以转换为【疑问词+不定式】结构.经常用于【疑问词+不定式】结构的动词主要有：ask,consider(认为）,decide,discover,explain,find out,forget,guess,inquire,know,learn,observe,remeber,settle,tell,think,understand,wonder 等.例如：
【 We 主句主语】haven't decided where 【we 从句主语】will hold the spors meet.
=We haven't decided where to hold the spors meet .
从以上分析可见,这种替换的实质是【复合句与简单句】的替换,而不是【情态动词+动词原形和to do替换】.