The Past Perfect Tense

• The form of the past perfect tense

This tense is formed with "Had" and the past participle :
S + had + V-ed
example :
(+) I had work at this office since last year.
(-) I had not work at this office since last year.
(?) Had you worked  work at this office since last year ?

• The use of the past perfect tense

1. the past perfect tense is used todescribe an activity that happened before other activities were done . example : I had swept the floor before my father came home from the office
2. the pas perfect tense is used after when if we wish to emphasize that the first action was completed before second one started. example : when he had seen all the pictures he said he was ready to leave. (it means we waited for the window to be quite shut before opening the cage)