内容正文:
Part Ⅲ Grammar and usage & Integrated skills
第一板块 Grammar—Toinfintives as subjects and predicatives
观察下列句中加黑的部分,然后完成后面的归纳。
①(教材原文P2)No matter how bad my mood is,that perfect combination is always enough to lift my spirits.
②(教材原文P2)If we grow up eating certain foods in our family,then those foods tend to be linked with positive emotions.
③(教材原文P3)According to some food experts,there are some aspects of culture that people will lose right away,but with food,there are more opportunities to connect to memory,family and place.
④(教材原文P3)It is hardest to give up the food that you grow up with.
⑤(教材原文P6)Not that long ago,my first thought at mealtimes was to eat at a restaurant.
⑥(教材原文P6)I was eager to try new restaurants.
⑦(教材原文P6)To eat out was also a social activity,allowing me to enhance the relationship with my friends.
【自我归纳】
1.例句①中动词不定式在句中作状语。
2.例句②和⑥中动词不定式在句中作宾语。
3.例句③中动词不定式在句中作定语。
4.例句④中动词不定式在句中作主语。
5.例句⑤中动词不定式在句中作表语。
6.例句⑦中第一个动词不定式在句中作主语;第二个作宾语补足语。
动词不定式
一、不定式作主语
通常表示个别的、具体的、一次性的或者具有将来含义的动作,并且句子谓语动词采用第三人称单数形式。常见的不定式作主语的情况主要有三类:
1.不定式直接作主语
To finish the work before Friday is not so easy.在周五之前完成这项工作没有那么容易。
本句中,主语是不定式to finish the work,谓语是is,采用单数形式。需要注意的是,动名词也可以作主语,但由于本句所表达的“在周五之前完成这项工作”是一种个别的、具体的、一次性的具有将来含义的动作,所以本句只能采用不定式作主语。
为了更好地理解不定式作主语与动名词作主语的基本区别,特别举例如下:
Smoking in public places is not good.
在公共场所吸烟不好。
本句采用动名词作主语,表示动作经常反复发生,而不是只针对某一次。
相反,之前不定式作主语的那个例句中,to finish the work所表达的是具体的个别的一次性的动作,而非经常反复性的动作。
2.it作形式主语,不定式作真正的主语
作形式主语时,有三种情况:
(1)常用形容词作它的表语。真正主语不定式通常有逻辑主语,一般用for短语来表示,即for sb.to do sth.(其中sb.就是to do的逻辑主语)。
It's important for us to keep the water clean.
保持水质清洁对我们来说很重要。
注意for不能用of来代替,因为不能说:You are important.
当表语形容词表示不定式的逻辑主语的性质或特征时,则不用for,而用of(sb.to do sth.)。 如:
It's very kind of you to say so.
你这样说真是太好了。
(可以说:You are very kind.)
(2)有时也接名词作表语。如:
It must be great fun to fly to the moon in a spaceship.
乘宇宙飞船飞往月球一定很有趣。
(3)it 作形式主语时,还常用于“It takes(took/will take)sb.some time(money)to do sth.”句型中。如:It took me more than an hour to do my homework yesterday evenin