1.I can't agree on your plan.
我不同意你说的
2.现在完成时的语言标志
have done sth.这是核心.时间标志是for sometime.其他标志yet,already.
例如:
I haven't finished my homework yet.
I have finished my homework already.
I have been here for many years.
过去进行时的语言标志
were/was doing sth.这是核心,指当时正在干什么.时间标志then,at that time等等.
一般过去时的语言标志
动词都是过去式了,时间状语也都是表示过去的,例如yesterday,in the past,three years ago等等.
一般现在时用动词原形或第三人称单数形式.标志词有：every day,evry Sunday,often,always,usually,sometimes ,on Sundays,on weekdays等等.
现在进行时am/is /are+v-ing形式.标志词：now,at the moment Look!,Listen!
一般过去时用动词的过去式.标志词有：yesterday,last week ,last month,last year,two years ago.
一般将来时用will +v(原形）.标志词：tomorrow,in the future,next week ,next Sunday.
过去进行时：was/were+doing 标志词：at that moment,at this time of yesterday,at eight last night.
过去将来时：would +do 没有什么标志词,通常用在从句里.
现在完成时：have/has+动词的过分词.标志词：ever,never,since,already,yet,before.twice,once ,three times.
过去完成时：had+动词的过去分词.此时态是发生在过去的过去,就是在过去之前发生的事.通常用在从句里.有时也有标志词：by the year 2000
while 一般表示主句和从句中两个动作同时发生,可译成“一边...,一边...”.过去进行和现在进行均可.e.g I am/was making notes while listening.
when 则用途更广,“同时；先；后均可”.e.g when he came in,I was reading a newspaper.
as 含有“伴随着...”.e.g As I am/was growing up,I learn a lot things.
过去时态中出现while,一般跟过去进行时.
注意：while还可用作转折连词“而”.所以见到它要看清楚.