Be -am/is/are -was/were -being -been 语法结构： 1. （don’t） be +形容词/名词短语 Be careful! Don’t be Careless. Don’t be sad. Don’t be an idiot. *告知人们如何表现或感受。 2 情态动词+be It should be a nice day tomorrow. He must be over fifty. There is someone at the gate. Who could that be? *谈论现在或将来状态的可能性和不确定性。 3. 情态动词+be+-ing I’ll be waiting for you this afternoon. I’ll be staying at the Intercontinental Hotel. *谈论现在或将来活动进行的可能性。 4. 情态动词+be +过去分词 Mobile phones should be turned off. The CEO will be interviewed on Monday. *谈论现在或将来可能的、必要的或期待的行为，而无须提及动作发出者。（被动语态的一种形式） 经常用于本结构的分词是：bothered, done, allowed, finished This assignment must be done before Friday. You won’t be allowed into the club without a tie. When will your house be finished? 5. 动词+to be I need to be there at 5. When he grows up, he wants to be a doctor. *接在后跟to的不定式后面，如want, hope, try, manage等。 固定短语： To be fair/to be honest/to be frank ect. 公平地、坦白地、坦率的