Unit2 Healthy Lifestyle不定式做主语课件（共21张PPT）选择性必修第三册（含音频+视频）.pptxVIP

;;不定式作主语基本用法：;1.不定式作主语通常表示一个将来的、具体的内容;

而动词-ing形式则表示一种经常性的、习惯的或抽象的概念。

Tolookafterchildrenisherjobtoday.

她今天的工作是看孩子。

Lookingafterchildrenisherwork.

她的工作是照顾孩子。;1.Toteachyoutheusesoftheinfinitiveismyjobtoday.(表具体行为)教你们不定式的用法是我今天的工作。

2.Teachingismyjob.(经常性行为)

教学是我的工作。;非谓语动词做主语：非谓语动词中的动词不定式和动词-ing形式作主语，一般谓语动词用单数。如果两个或两个以上的非谓语动词作并列主语，并且指两个或两个以上的动作时，谓语动词用复数。;[巧学活用1]——单句语法填空

①________(finish)readingthebookwilltakeyoutwohours.

②________(pay)avisittotheForbiddenCityismydream.

③Toimprovepeopleslivesandtospeedupsocialistconstruction_____(be)twoimportanttaskstoday.

④________(stay)uptoolateisabadhabitforourhealth.;2.当主语较长，谓语较短时，常用it作形式主语放在句首，而将真正的主语—不定式放到谓语的后面。

Toworkouttheproblemisnoteasy.

=It’snoteasytoworkouttheproblem.

Toplaywithsnowinwinterisinteresting.

=Itisinterestingtoplaywithsnowinwinter.

Tofinishthebuildinginamonthisdifficult.

=Itisdifficulttofinishthebuildinginamonth.;考点：it作形式主语常见的句型;Itisstupid_______themtoquarrelaboutthisquestion.

Itiseasy_______metolearnhowtodrive.

Itisimpolite______himtosayso.

Itisimportant_______ustoexpressouropinions.

Itisclever______himtoleavethatcompany.;2、接名词作表语：Itis+n.+todosth.;3.it作形式主语时，还常用于

“Ittakessb.sometime/moneytodosth.”句型中。;Itseems(appears)+形容词+todo

Itseemedimpossibletosavemoney.;[巧学活用2]——单句语法填空

①[2022·新高考卷Ⅰ应用文]Itismypleasure________(invite)youtoourEnglishshow“TalkandTalk”whichwillbeconductedat6a．m.thisFriday.

②Itisgoodmannersfortheyoung________(give)theirseatstotheold.

③Itismyambition________(make)surethatthedisabledpeoplehaveaccesstoallpublicbuildings.

④Itisnouse________(argue)withhim,forheissostubborn.;不定式作主语，有时根据表达的需要，可以在添加疑问代词或副词，

疑问代词：who，whom，what，which

疑问副词：when，where，how

whether

E.g.

Howtobreakthebadhabitisthequestion.

Wheretogohasntbeendisc