Be的肯定否定及疑问的变化
 
●The man  in the classroom教室 on the second第二 floor层  is  a teacher  from  England.
 
●The man  in the classroom on the second floor   is not
　a teacher  from  England.
 
●Is the man in the classroom on the second floor    
　a teacher  from  England ?
 
be 的人称变化
 
You  (They   We  )  are   teachers.
He  ( She )           　is    a teacher.
I                   　　　am   a teacher

Be的时态变化

● I am rich.      ● I was rich.   ● I will be rich.
 
Was(单数)  were(复数)
 
The man (men)  in the classroon on the second floor   is   a teacher  from  England.