有一读者问： 以不定代词，动词不定式、动名词作主语的陈述句，后面如何用反意疑问句？
很难笼统地谈这个问题。比如对下面几个句子中的主语即无法提出反意疑问句：
(1)To eat is to live.
(2)Seeing is believing.
(3)Anybody can do it.
如对全句发问，当然可说 Isn't that right? 或Don't you think so? 但这已不是附在句子后面的反意疑问句，而是独立的否定疑问句了。对下面一些句子中的主语倒是可提反意疑问句的：
(4)It is right to tell the truth, isn't it?（不定式短语在此是真实主语）
(5)Swimming is good exercise, isn't it?
(6)Everybody in that street can contribute some money, can't they?
