My hair is a mess! I _____ (look) in the mirror before I went out.
My hair is a mess! I SHOULD'VE LOOKED in the mirror before I went out.
Events that were possible in the past but didn't happen.
could have
1) do 2) meet
1) done 2) met
I could has stayed up late, but I decided to go to bed early.
I could HAVE stayed up late, but I decided to go to bed early.
I decided to study, even though I _____ (go) to the beach with my friends.
I decided to study, even though I COULD'VE GONE to the beach with my friends.
A good idea to do something in the past, but you didn't do it.
should have
1) go 2) drink
1) gone 2) drunk
Julie could have buy the book, but she borrowed it from the library instead.
Julie could have BOUGHT the book, but she borrowed it from the library instead.
I'm studying History at university, but if I'd got higher marks at school, I _____ (choose) Vet Science instead.
I'm studying History at university, but if I'd got higher marks at school, I WOULD'VE CHOSEN Vet Science instead.
Imagining something in the past that didn't happen (positive form).
would have
1) eat 2) begin 3) come
1) eaten 2) begun 3) come
Karen and Tim would'ave come, but I forget to tell them.
Karen and Tim WOULD'VE come, but I FORGOT to tell them.
Dean _____ (drive) home after the party last night. He drank too much alcohol.
Dean SHOULDN'T HAVE DRIVEN home after the party last night. He drank too much alcohol.
A bad idea to do something in the past, but you did it.
shouldn't have
1) throw 2) wear 3) wake
I feel really sick ... I shouldn't had ate so much cake!
I feel really sick ... I shouldn't HAVE EATEN so much cake!
If I'd known you were asleep, I _____ (call) you so early this morning.
If I'd known you were asleep, I WOULDN'T HAVE CALLED you so early this morning.
Imagining something in the past that didn't happen (negative form).
wouldn't have
1) freeze 2) fly 3) keep
1) frozen 2) flown 3) kept
If I knew you needed help, I could had came - you shouldn't tell me.
If I knew you needed help, I could HAVE COME - you SHOULD HAVE TOLD me.