关于动词作主语It's good for us to play sports every day.(要求改同义句)是不是可以改两种:To play sports every day is good for us.Playing sports every day is good for us.如果可以那么第二种包含的语法知识点是什么?

关于动词作主语It's good for us to play sports every day.(要求改同义句)是不是可以改两种:To play sports every day is good for us.Playing sports every day is good for us.如果可以那么第二种包含的语法知识点是什么? 动词不定式的逻辑主语for sb是作状语吗?例：It's a difficult question for you to answer.It's hard for you to learn.您的意思是for sb/of sb都是作状语吗？ It's no good smoking.(普通行为） It's not good for you to smoke here.(具体行为）、good、在两句话中分别作什么成分、不是、use,good,waste,fun,shame,unseless等名词作表语时,常用it作主语,且真正的主语必须用do 动词不定式与动名词作主语It's not easy _________a doctor for children.为什么用being,而不用to be? someone作主语,动词加不加S 关于动名词作主语的问题..动名词作主语,谓语动词用3单,比如Eating Dangshen and Huangqi herbs is also good for this.这里用的是is 但是要是有两个动名词同时作主语呢?比如Eating Dangshen herb and drink lots of wa 分析句子成分 It's good for your health to do more sports.这句话中for your health做什么成分?to do more sports 做主语； is 是系动词；it是形式主语； good是表语那么for your health是做什么成分的?句子还原后： It's a good time to climb hills中的It是不是形式主语那么It's a good season for flying kites中的it又做什么? 一般来说,动名词作主语 ：而在祈使句中动词也做主语 怎么区分?如 Reading English is good for your spoken 和 Close the window,piease. 动词作主语和表语的问题It's easier to read English that,it is () (speak) English.怎么填? it作形式主语的问题it 作形式主语的句型是 it + be动词,还是it + 谓语动词? It's fun to do sth.是将动词不定式做了主语,那么该动词不定式能改成动名词吗,为什么?因为It's fun to do sth=To do sth is fun.那么有没有It's fun doing sth呢?另外，Eating food is good for your health能不能改为It' It's good for our It's good for造句 it's good for 这是个梗吗? It's good for me 动词ing作主语 Its good for us ___after meals.括号内动词适当形式填空