1 	past perfect – something that happened before the main time of narration such as background 
information or an explanation 	I wish I hadn't gone to bed so late last night. 	
2 	past perfect - used to report a past statement 	I was tired because I hadn't slept for three days. 	
3 	past perfect after 'wish' - expresses a regret about the past	If I had gone to bed earlier, I wouldn't have been so tired. 	
4 	past perfect - used in a past conditional structure 	She said she had called earlier. 	

I knew I'd seen his face somewhere before. 

We didn't stay up to watch the film as we'd already seen it. 

I wish I hadn't eaten so much. 

They said they'd seen the film before. 

I was filthy as I'd been fixing my car. 

When Tim got there, we'd nearly finished the cleaning up. 

I was coming back from London where I'd been visiting friends 

I wish you'd told me before. 

He told me he'd tried to call you three times 

If I'd known it was your birthday, I'd have bought you a present 

I could see straight away that he'd been drinking. 

I wish I had more money. 

Answers	

1	past perfect – something that happened before the main time of narration such as background information or an explanation	I was tired because I hadn't slept for three days.

I knew I'd seen his face somewhere before. 

We didn't stay up to watch the film as we'd already seen it. 

I was filthy as I'd been fixing my car. 

When Tim got there, we'd nearly finished the cleaning up. 

I was coming back from London where I'd been visiting friends.

I could see straight away that he'd been drinking.	
2	past perfect - used to report a past statement	She said she had called earlier.

They said they'd seen the film before.

He told me he'd tried to call you three times.	
3	past perfect after 'wish' - expresses a regret about the past	I wish I hadn't gone to bed so late last night.

I wish I hadn't eaten so much.

I wish you'd told me before. 

I wish I had more money. 	
4	past perfect - used in a past conditional structure	If I had gone to bed earlier, I wouldn't have been so tired.

If I'd known it was your birthday, I'd have bought you a present.