1)雅思阅读动词不定式的构成：(以动词“do”为例)
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.(：=It seems that he knows her address.)
I hope to see you again.(=I hope that I’11 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 year’s time.(I hope 1 will/would be earning my living)
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.[据认为(据知，据信，据说，据猜测)她住在国外。]
[注]“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 shouldn’t cook in their dormitory.
