to do不定式的用法。
语法（二）不定式todo的用法一：动词不定式的意义和结构1.不定式的语法意义：（1）在句中做以下成分：主语，宾语，表语，补足语，定语，状语（2）一“无”一“有”：无人称和数的变化有时态和语态的变化（3）仍然保留动词的特点：to—vt+主语；to—vi（+状语）2.结构：肯定式todo；否定式not\\\ evertodo二：不定式的时态和语态变化时态：与谓语动词相比，动词不定式的时间在谓语动词之前，同时之后进行。
1.一般式：动词不定式表达的动作发生在主句谓语动词之后或同时发生。
2.完成式：动词不定式表达的动作发生在主句谓语动词之前。
eg：I’msorrytohavekeptyouwaitingsolong.3．进行式：动词不定式表达的动作发生在主句谓语动词之前。
eg:Theyseemtobegettingalongquitewell.4.完成进行式：动词不定式表达的动作发生在主句谓语动词之前且进行.语态：动词不定式与主句主语的关系三．句子结构（一）主语：1.不定式作主语，谓语动词用单数（非谓语动词todo，doing，done只有前两者可以作主语，done相当于形容词）。
2.不定式作主语，常用it形式主语，把todo放于句尾。
句式：（1）Itis+形容词+forsb.todosth.做某事对于某人来说是怎样的，此处为客观性质的形容词，如：hard，difficult，easy等（2）Itis+形容词+ofsb.todosth.意思同上，此处为表示人得性格，本质特征，如：kind，friendly，selfish等Eg：1>I
不定式的用法
动词不定式用法归纳动词不定式没有人称和数的变化，在句中不能独立作谓语。
但动词不定式具有名词、形容词和副词特征，在句中可以作主语、宾语、宾语补足语、定语、表语和状语等多种成分。
另外，动词不定式具有动词特点，可以有自己的宾语和状语，组成动词不定式短语词不定式的肯定形式是to＋do；其否定形式是not to＋do。
1．作主语 可以直接作主语。
如： To see is to believe． 但在英语中，常用it作形式主语，真正的主语即动词不定式放在后面。
如： It's wrong to play tricks on other people． It's our duty to keep our environment clean and tidy．（Lesson 10）． 点击规律：动词不定式在句中作主语时，常放在It is ＋adj．（形容词）＋to do sth．或 It is ＋n．（名词）＋to do sth．句型中，it仅作形式主语。
2．作宾语 a.以下动词只能to do 作宾语。
attempt企图 enable能够 neglect忽视 afford负担得起 demand要求 long渴望 arrange安排 mean意欲，打算 begin开始 expect期望 appear似乎， 显得 determine决定 manage设法 cease停止 hate憎恨，厌恶 pretend假装 ask问 need需要 agree同意 desire愿望 love爱 swear宣誓 volunteer志愿 wish希望 bear承受 e
动词不定式 以 it is+形容词+to do sth.造两个句子
it is+形容词+to do sth.译作 做。
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事 是。
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的It is easy to answer these questions 回答这些问题很简单It is hard to study English。
学习英语是困难的。
itis十形容词十for\\\/ofsbtodosth什么意思
用for 是因为前面的adj是来描述do后面的sth.用of 的话,adj就用来形容sb的it is adj of sb to do,这里的形容形容人的性格特征的,如nice,kind clever,foolish,smart,都是形容人的,it is adj for sb to do就是普通的形容词,如hard,impossible,important翻译：对我们来说学习英语太难了it is+adj+for sb to do...it is+adj+of sb to do ....的含义及区别一.导入It is kind of you to help me.你能帮我太好了.（kind 形容的是you）It is beneficial for you to do sports.运动对你有益.（beneficial形容的是do sports）二.表达含义:1.it is+adj+for sb. 就是“做…对某人(for sb)来说怎么样(adj)”2.it is+adj+of sb. 就是“某人做…(of sb)怎么样(adj)”三.辨析:it is+adj+for sb和it is+adj+of sb.①“It’s +adj.+of+sb.+不定式”表示“某人(做某事)怎么样” 一般用表示人物的性格,品德.表示主观感情或态度的形容词.若形容词是描述逻辑主语(行为者即of后的sb)的性格、品质特征的形容词. 这个adj.是用来形容sb.的.of后的宾语能与前面的形容词构成主表关系. 这类形容词有:good(好的),kind(友善的),nice(友好的),polite(有礼貌的),clever(聪明的),foolish(愚蠢的),lazy(懒惰的), right(正直的)careful(细心的),careless(粗心的),right(正确的),wrong(错误的)wise, clever, nice, kind, silly,rude, wrong, right, foolish,natural, stupid, bad, brave,cruel, honest,naughty,wise,rude等.例如:It’s very kind of you to help me.(=You are very kind to help me.)你能帮助我,真好.It's very kind of you to look after my cat.你能照看我的猫,真好.It’s kind of you to say so.(=You are kind to say so)It’s very rude of her to say such words.(=She is very rude to say such words.)她说这样的话,真粗鲁.It’s foolish of him to go alone.(=He is foolish to go alone.)他单独出去太傻了.It's very nice of you to help me. 你来帮助我,你真是太好了.It’s clever of you to work out the maths problem. It's very kind of you to look after my cat.你真聪明,解出了这道数学题.It’s foolish of you to do that.It’s wrong of the other children to make fun of you.②“It’s+adj.+for+sb.+不定式”表示“做某事对某人来说怎么样”.常用于表示事物的特征特点,表示客观形式的形容词.若形容词是描述做的事情（即adj描述的是to do）,不是对不定式行为者的品格进行评价,用for sb.这类形容词有:important(重要的),necessary(必要的),difficult(困难的),easy(容易的),hard(艰难的),dangerous(危险的),safe(安全的),useful(有益的),pleasant(舒适的),interesting(有趣的),impossible(不可能的),right(正确的) likely(可能的)等，例如:It’s not easy for them to learn a foreign language.(=To learn a foreign language is not easy for them.)对于他们来说学好一门外语不容易.It's very hard for him to study two languages(=To study two languages is very hard for him).对他来说学两门外语是很难的.It’s very important for students to listen to teachers carefully.(=To listen to teachers carefully is very important for students.)对于学生来说上课认真听老师讲课是非常重要的.It’s necessary for us to get to school on time.(=To get to school on time is necessary for us.)对于我们来说按时到校是非常必要的.It’s important for her to come to the party.=It is important that she should come to the party.对她来说来参加聚会很重要.It’s very dangerous for children to cross the busy street.对孩子们来说,穿过繁忙的街道很危险.It’s difficult for us to finish the work. 对我们来说,完成这项工作很困难.③注意:for 与of 的辨别方法: I.区别:1.含义上的区别:两种句型的主谓关系不一样.It is+adj+for sb to do. adj应该是对做这件事的评价;It is+adj+of sb to do sth. adj应该是对做这件事的人的评价,adj多用形容人的.①It is +adj+for sb to do sth. 形容词(for前的)是多用来形容一件事情(动词不定式所表示的动作),即修饰的是 to do sth. adj是do sth.的属性; sb.跟adj.没有直接联系. for是指干谋事会如何.It's plesant for us to take a walk after supper.②It is+adj+of sb to do sth. 形容词(of前的)是多用来形容人的;修饰的是介词of后面接的宾语. sb.跟adj.有直接联系.③实例辨析:It's very difficult for me to do it. (difficult 指事情很难)It's very kind of you to do it for me. (kind指人的品质好)It is more convenient for him to walk directly.对他来说,直接走过来比较便捷. (convenient 指事情很便捷)It is clever of him to come down without ropes.他很聪明,不用绳子就能下来. (convenient 指指人很聪明)2.逻辑结构上的区别:方法:取介词of\\\/for后的代词作逻辑主语和介词前边的形容词作表语,造个句子.句子结构:“逻辑主语+be+形容词”.即:sb.is adj to do sth (不定式作句子的状语).如果道理上通顺用of,不通则用for.如:It is good for you to look at this book. 是说: ....对你有好处. 看这本书对你有好处.It is nice of you to give me such advice.是说: 你很好,感激你给我提供建议.*提取逻辑主语和形容词造句:It is nice of you to help me. 提取you与nice 可构成you are nice. (通顺,所以应用of).It's very kind of you to help me. 提取you与kind可构成you are kind. (通顺,所以应用of).It is good for you to look at this book.提取you与good可构成you are good(有好处的). (不通,所以应用for)It is hard for him to study two languages. 提取he与hard可构成he is hard(困难的). (不通,所以应用for)四.注意:of sb. 的句型通常都可转换为不定式作状语的句子,但for sb.句型不可以. It’s very nice of you to offer me a seat. = You are nice to offer me a seat. 十分感谢你给我让座. It is careless of him to lose so many things. = He is careless to lose so many things. 他丢了这么多东西,真是太粗心了. It’s very important for you to practise your oral English in daily life.
it +形容词+to do sth 和it is +形容词+to do sth 有什么区别?
it+形容词+to do 中的it是形式宾语，而adj.做宾语补足语，to do sth是真正的宾语。
例如，I found it hard to solve this problemit is+ 形容词+to do 中的it 是形式主语。
例如，It is easy to get along with her. 如果在宾语从句中应该表达成 I found (that) it is easy to get along with her=I found it easy to get along with her.
sb.todo中的todo各是做什么句子成分谢
It is important to learn English well .学好英语很重要。
