语态：只有两个,被动与主动.
被动语态的构成,be+p.t
be动词可以依时态的改变而改变.过去时用was或是were.一般时就用am,are,is.
时态
一般现在时.主谓宾,或是主系表.
现在进行时,be+V-ing.
eg；I am reading.I am going to leave.
现在完成时,have+p.p
eg：I have studied English for seven years.
现在完成进行时：have+been+v-ing.
ag：I have learning English for seven years.
一般过去时,主系表.be动词用was/were
eg：I was a student.
主谓宾.行为动词用过去式就行了
eg：She went to school by bike this morning.
过去进行时,was/were+v-ing
eg：when I called him,he was cooking.
过去完成时,had+p.p.
eg：Before she eat breakfast,her kid had gone to school.
一般将来时,be+going to do sth.或是 will do sth
eg：I am going to Beijing
/I will go to Beijing one day.
语态是不受时态限制的.顺便说下,情态动词的被动语态
should/must/could+be +P.P
eg：The classroom must be cleaned every day.
