2016-2017学年 北师大版 选修6 unit16 Stories lesson4 课件 (1)
2016-2017学年 北师大版 选修6 unit16 Stories  lesson4  课件 (1)第2页

Grammar summary

To talk about an event or situation in the past which happened before the other past.

Use:

now

past

Past perfect

form

had + done

had + been done