Past Perfect

First, I wrote a letter. Second, I showed him the letter. ⇒ I showed him a letter that I​​ (a)  

• d´ written
• wrote

First, I wrote a letter. Second, I showed him the letter. ⇒ I wrote a letter and a few days later I ​ (a)   it to him.

• showed
• had shown

First, I looked through the window. Second, it started raining. ⇒ When I looked through the window, it ​ (a)   raining.

• started
• had started

First, it rained. Second, I looked through the window. ⇒ When I looked through the window, it ​ ​ (a)  

• had rained
• rained

First I had dinner. Second, you called. ⇒ When you called, I ​ (a)   dinner.

• ´d had
• had

First you called. Second, I had dinner. ⇒ When you called, I ​ (a)   dinner.​

• had
• ´d had

First, she bought a T-shirt in the sales. Second, she gave it to me. ⇒ She bought a T-shirt in the sales and ​ (a)   it to me as a birthday present.

• gave
• had given

First, she bought a T-shirt in the sales. Second, she gave it to me. ⇒ She gave me a T-shirt that she ​ (a)   in the sales.

• had bought
• bought

First, the teacher arrived. Second, I finished my composition. ⇒ When the teacher arrived, I ​ (a)   my composition.

• finished
• 'd finished

First, I finished the composition. Second, the teacher arrived. ⇒ When the teacher arrived, ​ (a)   my composition.​

• I 'd finished
• finished