写英语作文的时候怎样才能保持时态一致?英语语法有什么时态?分别是怎样的?
时常检查.英语时态有16种：一般现在时、一般过去时、一般将来时、过去将来时、现在进行时、过去进行时、将来进行时、过去将来进行时、现在完成时、过去完成时、将来完成时、过去将来完成时、现在完成进行时、过去完成进行时、将来完成进行时、过去将来完成进行时.
（1）一般现在时
基本形式（以do为例）：
第三人称单数：does（主语为非第三人称单数）；
肯定句：主语＋动词原形＋其他；
He works for us.
否定句：主语＋don‘t/doesn't＋动词原形＋其他；
He doesn't work for us.
一般疑问句：Do/Does＋主语＋动词原形＋其他.
肯定回答：Yes,（＋ 主语＋do/does）．
否定回答：No,（＋主语＋don't/doesn't.）
特殊疑问句：疑问词+一般疑问句语
Does he work for us?
Yes, he does.
No, he doesn't
What does he do for us?
He works for us.
（2）一般过去时
be动词＋行为动词的过去式
否定句式：在行为动词前加didn‘t,同时还原行为动词,或was／were＋not；
was或were放于句首；用助动词do的过去式did提问,同时还原行为动词
例如： Did he work for us?
He didn't work for us.
He worked for us.
（3）一般将来时
am／are／is＋going to＋do 或
will／shall＋do
am/is/are/about to + do
am/is/are to + do;
一般将来时的表达方法
be going to +动词原形
be +不定式,be to+动词原形,be about to ＋动词原形
be able to +不定式
be about to+动词原形
will + 动词原形；
例如：He is going to work for us.
He will work for us；
He is coming.这是特殊的用一般现在时 表达 将来时态 的例子!
(4)过去将来时
be（was,were）going to+动词原形
be（was,were）about to+动词原形
be（was,were）to+动词原形
肯定句：主语+be（was,were）going to+动词原形～.
否定句：主语+be（was,were）not going to+动词原形～.
疑问句：Be（Was,Were）+主语+going to+动词原形～?
肯定句：主语+would（should）+动词原形～.
否定句：主语+would（should）not+动词原形～.
疑问句：Would（Should）+主语+动词原形～?
He would work for us.
(5)现在进行时
主语+be+v.ing〔现在分词〕形式(其中v表示动词)
表示现在正在进行的动作或最近在做的事.
例如：I am buying a book.
第一人称+am+doing+sth
第二人称+are+doing +sth （doing是泛指所有的v-ing形式）
第三人称+is+doing+sth
例：He is working.
(6)过去进行时
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.
(8)过去将来进行时
should(would)+be+现在分词
He said that he would be working for us.=He said that he would work for us.
(9)现在完成时
基本结构：主语+have/has+过去分词(done)
①肯定句：主语+have/has+过去分词+其他
②否定句：主语+have/has+not+过去分词+其他
③一般疑问句：Have/Has+主语+过去分词+其他
④特殊疑问句：特殊疑问词+一般疑问句（have/has+主语+过去分词+其他\
He has worked for us for ten years.
Has he worked for us for ten years.
(10)过去完成时
基本结构：主语+had+过去分词(done)
①肯定句：主语+had+过去分词+其他
②否定句：主语+had+not+过去分词+其他
③一般疑问句：Had+主语+过去分词+其他
肯定回答：Yes,主语+had
否定回答：No,主语+hadn't
④特殊疑问句：特殊疑问词+一般疑问句（had+主语+过去分词+其他）
语法判定:
（ 1 ） by + 过去的时间点.如：
I had finished reading the novel by nine o'clock last night.
（ 2 ） by the end of + 过去的时间点.如：
We had learnt over two thousand English words by the end of last term.
（ 3 ） before + 过去的时间点.如：
They had planted six hundred trees before last Wednesday.
(11)将来完成时
（shall）will+have+动词过去分词
before+将来时间或by+将来时间
before或by the time引导的现在时的从句
He will have worked for us.=He will work for us.
(12)过去将来完成时
should / would have done sth.
He said that he would have worked for us.=He said that he would work for us.
(13)现在完成进行时
基本与现在完成时相同,但是现在完成进行时只能表示仍然持续的概念
have/has been +-ing 分词
He has been working for us for ten years.=He has worked for us for ten years.
(14)过去完成进行时
had been +-ing 分词
He said that he had been working for us for ten years.=He said that he had worked for us for ten years.
(15)将来完成进行时
主语+ shall/will have been doing
He will have been working for us.=He will work for us.
翻译为：他最近一直在为我们工作（过去在工作,现在在工作,将来还会工作）
(16)过去将来完成进行时
should+have been+现在分词用于第一人称
would have been+现在分词用于其他人称
He said that he would have been working for us.=He said that he would work for us.
（来自文库）
