1.做主语:
• To live is to work. • To save time is to lengthen life.
To do 不定式做主语,谓语动词用单数形式
1.做主语:
形式主语
It is a great pleasure to play basketball.
即:It is /was +adj/n + to do 真正主语
8.虚拟语气在其他句型中:
过去相 1要.I是f o我nly通I过ha了d上pa过周ss去e的d完驾th成驶e d考riv试in就g t好es现t了l在反a!st或w将ee来k! 相反 2.(2016·10浙江)If only she had not left her mobile phone
in that bag with Tom. 要是她没把手机落在汤姆的那个包里就好过了去!
3.做宾语(跟在某些动词后):
hope, want , expect, desire, like, love, dislike, hate, plan, intend, mean, prepare, decide, determine, afford, fail, manage, try, dare, help, promise, refuse, learn, offer, agree, forget, bother, ask, beg, decide, seem, wish, demand, refuse, manage, happen......
为使句子平衡,常ቤተ መጻሕፍቲ ባይዱ it 作形式主语, 把真 正的to do不定式主语移到句子后部去.
2.做表语:
1. He is to marry Rose. 表示按计划和安排将要发生的事情。 2.Her wish was to become an artist. 表示主语的内容,但侧重于目的性 3.The form is to be filled in and returned within a week. 表示情态意义(应该, 必须)