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课件网) Unit 1 Food matters Grammar and usage 1.As a real foodie, I enjoy all kinds of foods. My dream is to try different restaurants and taste various foods. 2.Yesterday I invited some friends to try a great new restaurant for dinner. 3. We arrived at the restaurant, only to see a huge line of people waiting to get into the restaurant. 4.Nothing can stop our determination to have a try. We decided to wait outside. 5. After an hour of waiting, we were invited to go into the restaurant and take the order. 6.The dishes are extremely delicious. It is worthwhile to have such a long wait. 指出下面句子中不定式所做的成分。 根据第1,6句，我们可以知道： 1）To-infinitives可以做 ，通常跟在 动词之后。 2） To-infinitives 在句子中还可以做 ，为了保持句子平衡，通常把To-infinitives放在句末，用 做形式主语。 表语 be 主语 it Exploring the rules Below is a blog entry about eating out and eating at home. Find the sentences that use to-infinitives as subjects. To-infinitives as subjects To eat out was also a social activity, ... To-infinitives as predicatives ..., my first thought at mealtimes was to eat at a restaurant. My plan is to invite my friends over at the weekend ... ..., it was not that difficult to make a simple and tasty dish. Exploring the rules Working out the rule When the to-infinitive is used as a subject, we usually use the preparatory subject (1) at the beginning of the sentence. The to-infinitive can also be used as a predicative. It usually comes after the verb (2) . be Exploring the rules it 1.动词不定式具有名词特征，可充当主语。（做主语时谓语动词用单数形式） To see is to believe. 眼见为实。 注：单个不定式作主语时，谓语动词用单数形式；两个及以上不定式作主语时，谓语动词用复数形式；但作为一个整体时，谓语动词用单数形式。 到哪里去度假以及何时去度假还没有决定。 Where to go on a holiday and when to go for the holiday (decide). 到哪里去，何时去度假还没有决定。 Where and when to go on a holiday_____(decide). To say is one thing and to do is another. 说是一回事，做又是另一回事。 have not been decided has not been decided 动词不定式作主语 2.动词不定式做句子的主语时可以用形式主语it代替，将不定式置于句末， 平衡句子结构。 It is a shame to litter. 乱扔垃圾可耻 It is a privilege to meet you. 认识你很荣幸 动词不定式作主语 1. 被邀请到你家做客真的是太荣幸了。 It is a great honour to your family. to be invited to prepare for It is + n.(a pity, a shame, an honour …) to do sth It takes sb some time/money… to do sth it 作为形式主语时，常见句型有： 2.在家做饭准备环节需要花很长时间。 It takes a long time home-cooked meals. 3.你为我们做了这么多美味的菜真的是太好了。 It is nice ____ you _____ so many tasty dishes for us. 4.在当今社会，我们学会做饭还是很有用的。 It is useful _____ us . to learn how to cook for of to make It is + adj.+ for/of sb to do sth Attention! 3.动词不定式做句子的主语时, 若其后面需要用动词作表语时，则作表语的动词也最好使用不定式形式，保持形式一致 (to do is to do) To save me is to save yourself. ... ...
