在英语中，"of...to do sth." 和 "for...to do sth." 结构是表达行为或状态的两种重要语法形式。它们在句中可以承担不同的语法角色，如主语、表语、宾语、定语或状语。这些结构不仅丰富了句子的表达，还帮助我们更精确地描述行为和行为者之间的关系。
<例句>
It is careless of you to lose so much
money.
你太粗心，掉了那么多钱。
<语法分析>
of...to do sth.用在句中作主语，可接形容词作表语。it作形式主语。而for...to do
sth.除了在句子中作主语外，还可以作表语、宾语、定语和状语等，作主语时，其表语可以使形容词，也可以是名词。有些形容词，如nice, right, wrong,
good和wise等都可用于这两个结构中，但是意思有所差异。
<触类旁通>
(1) It's very kind of you to help
me.
你帮助我真是太好了。
语法分析：of...to do sth.结构用在句中作主语。
(2) My suggestion is for you to do your
homework.
我建议你去做家庭作业。
语法分析：for...to do sth.结构在句子中作表语。
(3) I'd like for you to come here.
我想还是你来这里好。
语法分析：for...to do
sth.结构在句子中作宾语。
(4) He has a lot of work for you to do.
他有很多活要你来做。
语法分析：for...to do
sth.结构在句子中作定语。
(5) He opened the door for the students to come
in.
他开门让学生进来。
语法分析：for...to do sth.结构在句子中作状语。
(6) It is important for your teachers to attend today's
meeting.
参加今天的会议对你的老师很重要。
语法分析：在for...to do
sth.结构中，不定式的逻辑主语可以是人或物，也可以是引导词there。
(7) You are kind to lead the blind man across the
road.
你真是好心人，把盲人引过马路。
语法分析：for...to do
sth.结构中，后面的名词或代词与前面的形容词有逻辑上的主表关系。
<巩固练习>
(1) It is impossible for you to get there in such a short
time.
(2) It will be a mistake for me not to help them.
(3) It is possible
for us to spend three hours completing the composition.
(4) It will take
three hours for us to complete the composition.
(5) It is a good idea for the
present to be given to her.
(6) It is a pity for there to be any disagreement
in the company.
(7) It is wrong of the hunter to kill the monkey.
<参考答案>
(1) to get (2) to help (3) completing (4) to complete (5) to
be given (6) to be (7) to kill
通过这些练习和分析，我们可以更深入地理解 "of...to do sth." 和 "for...to do sth." 结构的用法，并在实际的英语写作和口语中更加灵活和准确。