雅思阅读知识点：动词不定式

　 1)雅思阅读动词不定式的构成：雅思阅读动词不定式的构成：

　　主动态：一般式to do；完成式to have done；进行式to be doing；完成进行式to have been doing

　　被动态：一般式to be done；完成式 to have been done

　　否定式：not+不定式

　　2)雅思阅读不定式的时态：

　　①不定式的一般式表示的动作与主句谓语动词表示的动作同时发生或之后发生。

　　He seems to know her address.

　　I hope to see you again.

　　②不定式的进行体表示的动作正在进行，与主句谓语动词表示的动作同时发生。其用法主要有以下几种情况：

　　a 常用在appear，happen，pretend，seem，hope，promise之后。

　　She pretended to be listening attentively.

　　Tom appeared to be living in this area.

　　I hope to be earning my living in a years time.

　　I promised to be waiting at the door when he came out.

　　b 常用在believe，consider，suppose，think，know，report，say，understand等动词的被动式之后。

　　He is thought/known/believed/said/supposed to be living in this area = People think/know/ believe/ say/suppose that she is living abroad.

　　be supposed to通常含有应该意思，表示一定的责任和义务，在雅思阅读中出现的很多。

　　You are supposed to know how to use a computer=You should know how to use a computer.

　　You are supposed to have been studying=You should have been studying.

　　Students are not supposed to cook in their dormitory=Students shouldnt cook in their dormitory.