Unit2Discoverusefulstructures语法课件- 高中英语人教版（2019）选择性必修第三册.pptx

B6 U2 Grammar不定式作主语To see is to believe.百闻不如一见。To get up early is necessary.早起是必要的。To learn a skill is very important for everyone in society.1.To see is to believe.2.To get up early is necessary.1.动词不定式作主语单个不定式作主语时,谓语动词用_数。单To see is to believe.百闻不如一见。To get up early is necessary.早起是必要的。To learn a skill is very important for everyone in society.1.How to use the computer is the question.2.Where to go has not been decided.2.疑问词who,whom,whose,what,which,when,where,how+to do不定式短语作主语时,谓语动词用_数。单To see is to believe.百闻不如一见。To get up early is necessary.早起是必要的。To learn a skill is very important for everyone in society.Its not easy to work out the problem.=To work out the problem is not easy.3.用it作形式主语放句首若不定式太长,往往用it作_,不定式后置。形式主语Its important for us _(learn)English well.to learnIts+adj+for sb+to do(_,_,_,_)difficulteasyimportantnecessary It is+adj+for/of sb to do sth.1.It is necessary for young students to learn a foreign language.2.It was silly of you to give up such a good chance！Its+adj+for sb+to do(_,_,_,_)difficulteasyimportantnecessaryIts+adj+of+sb+to do(_,_,_,_,_)kindfoolishfriendlyrudepolite It is+n.+(for sb.)to do sth.1.It is a pity for you to miss such a wonderful film.2.It is a great fun for you to visit the exhibition.pity,shame,pleasure,ones duty,fun,joy,good manners,bad mannersIt takes/took/will take sb.some time/money to do sth.做某事花费某人多长时间(钱)1.It took me more than an hour to do my homework yesterday evening.2.It will take us a lot of money to buy that house.Thank You！Please take note.