Past Perfect Tense

Tense : Past Perfect Tense 过去完成式

Formula : -verb to have (had) + past participle (4^th column of the verb list)
                 
                   I / You / We / They/ He / She / It had
                  Ex: had forgotten
                        had bought

Usage :  -An action which has happened/ completed in the past
       在过去的时刻里刚刚完整发生的一件事、已经完成的一个动作。

Examples : a) -I had already eaten pizza.
                       我已经吃了批萨。（昨天你刚到家的时候，我已经吃了批萨）

                    b) -When I reached the railway station, the train had left.

Keywords : -already

Exercise :
Complete the sentences in Past Perfect Simple (positive).

1. I lost the key that he(give) ______________ to me.
2. She told me that she(see) _______________ a ghost.
3. I went downstairs because I(hear) _________________ a noise.
4. When they came home, Sue(cook) ________________ dinner already.
5. We could not send you a postcard because we(forget) ______________ our address book.   

1.