think作“想，考虑”解时，可用于进行时态。如： I?m thinking about it now.我现在正在考虑这事。 Do you know what he is thinking about? 你知道他在想什么吗？
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过去进行时
进行的行为或动作。
间状语等。
3.基本结构：was/were+doing
4.否定形式：was/were + not + doing.
1.概念：表示过去某段时间或某一时刻正在发生或
2.时间状语：at this time yesterday, at that time或以when引导的谓语动词是一般过去时的时
5.一般疑问句：把was或were放于句首。
6.例句：At that time she was working in a PLA unit.
When he came in, I was reading a newspaper.
肯定句：主语+was/were+doing+其它 否定句：主语+was/were+not+doing+其它 一般疑问句及答语：Was/Were+主语+doing+其它 ；答语：Yes,I主语+was/were./No,I主语+wasn't/weren't.
特殊疑问句：特殊疑问词+was/were+主语+doing+其它
He was working when he was alive.
(7)将来进行时
主语+will + be +现在分词
He will be working for us.=He will work for us.
六、 过去进行时的用法
过去进行时的用法与现在进行时用法相同，只不过参照的时间基准点不同。
（1）过去进行表示过去某一时刻正在进行的动作。一般和特定的时
间状语或状语从句连用。如：then, at that time, at eight yesterday, this time yesterday, when he came in等。
I was playing volley-ball this time last Sunday.上周日的这个时候我正在打排球。
Li Fang was watching TV when her father came back.李芳的爸爸回来时她正在看电视。
（2）过去进行时表示过去某段时间是持续进行的动作。 They were making ships last month.他们上个月正在造船。 （3）go, come, leave等瞬间动词的过去进行时表示过去某一时点安排或计划好的即将发生的动作。
The plane was arriving at eight.飞机八点到达。 过去进行时与一般过去时的区别
过去进行时表示过去某一动作正在进行，强调“动作的连续性”，而一般过去时则表示一个完成的动作，强调“有过这件事”。 I was playing chess last night.昨晚我在下棋。 I played chess last night.昨晚我下棋了。
My father worked last Sunday. 我爸爸上周日工作了。 My father was working last Sunday. 我爸爸上周日在工作着。 七、 现在完成时的用法
（1）表示动作已经完成，但后果或影响仍在。常与already, just, yet等副词连用。
I have just read your letter.我刚刚读完你的信。
He has already come back.他已经回来了.
(2）表示过去发生的动作一直持续到现在。常与for或since引导的一段时间状语连用。
He has lived here for three years.他在此住了两年了。 I have been here since 1976.自从1976年我就一直在这里。 ①．for后通常跟一个时间段，而since后只能跟一个具体的时间点。
如：for two weeks持续两周时间；since Monday自从周一 ②．现在完成时的肯定句，其谓语动词如果是瞬间动词，如come, go, begin, join等，则不可与表示一段时间的状语连用。 如：他到此两周了：He has arrived here for two weeks.（×） 此时需转换表达方式：
①用ago代替for，并改为一般过去时 ②用延续性动词代替瞬间动词
③用It is/It has been…since…句型，如： He arrived here two weeks ago. He has been here for two weeks.
It is/It has been two weeks since he arrived here. 当瞬间动词用于否定句时，则可以与时间段连用。如： I haven?t gone there for six years.我六年没去那儿。 （3）表示过去发生过一次或多次的动作已成为某种经验。 I have been to Paris twice.我去过巴黎两次。
It?s one of the most interesting films I?ve ever seen.它是我看过的最有趣的电影之一。
比较have been to与have gone to
have been to表示“去过某地”，现在已回来了，可以与ever twice等词连用。如：
I have ever been to London.我曾去过伦敦。
have gone to表示“去某地了”现在尚未回来，不能与ever, twice等词连用。
He has gone to London.他去伦敦了。 现在完成时与一般过去时的区别 二者都表示“动作已经发生”，区别在于：
（1）现在完成时强调这一动作与现在的关系，即对现在产生的结果、影响等，而一般过去时只表示过去的事实，不表示和现在的关系。 He has learned French for three years.他学法语已三年了。 He learned French for three years.他曾学过三年法语。 Who has taken my bag? I couldn't find it. 谁拿走了我的包？我找不着了！
He cleaned the house yesterday. 他昨天打扫过房间。 The room is clean, for he has cleaned it already. 房间很干净，因为他已经打扫过了。
（2）现在完成时不可与表示过去的时间副词连用，而一般过去时则可以。