一般现在时:主语＋be+--
           主语＋do/does sth---
现在进行时：主语＋be+doing sth ---
现在完成时：主语＋have/has +过去分词＋－－－
一般过去时：主语＋be+--
            主语＋did sth+---
过去进行时：主语＋be+doing sth + ---
过去完成时：主语＋had +done sth ---
一般将来时：主语＋be going to do sth ---
            主语＋will/shall do sth ---
            主语＋be going to do sth ---
            主语+would/should do sth ---
被动语态：主语＋be done ---
　　　　　主语＋be done ---
           主语＋be being done ---
          主语＋have/has/had been done ---
说明：do泛指动词原形，does泛指动词单三现，did泛指过去式,doing泛指现在分词，done泛指过去分词．
现分别举例如下：
I am a student。
  He is in the room。They are not here。She was a girl。I work hard。She works hard。I am studying math。They were studying math。
  They are going to study math。We have studied math 。You had studied math。He will study math。She would study math 。Math is studied by us。
  Math was being studied by us。Math has been studied by us 。
                                
            。