I could shrink you could shrink he could shrink we could shrink you could shrink they could shrink
V-ing form
I could be shrinking you could be shrinking he could be shrinking we could be shrinking you could be shrinking they could be shrinking
Perfect
I could have shrunk you could have shrunk he could have shrunk we could have shrunk you could have shrunk they could have shrunk
V-ing perfect
I could have been shrinking you could have been shrinking he could have been shrinking we could have been shrinking you could have been shrinking they could have been shrinking
Negation
Simple form
I couldn't shrink you couldn't shrink he couldn't shrink we couldn't shrink you couldn't shrink they couldn't shrink
V-ing form
I couldn't be shrinking you couldn't be shrinking he couldn't be shrinking we couldn't be shrinking you couldn't be shrinking they couldn't be shrinking
Perfect
I couldn't have shrunk you couldn't have shrunk he couldn't have shrunk we couldn't have shrunk you couldn't have shrunk they couldn't have shrunk
V-ing perfect
I couldn't have been shrinking you couldn't have been shrinking he couldn't have been shrinking we couldn't have been shrinking you couldn't have been shrinking they couldn't have been shrinking
Interrogative form
Simple form
could I shrink? could you shrink? could he shrink? could we shrink? could you shrink? could they shrink?
V-ing form
could I be shrinking? could you be shrinking? could he be shrinking? could we be shrinking? could you be shrinking? could they be shrinking?
Perfect
could I have shrunk? could you have shrunk? could he have shrunk? could we have shrunk? could you have shrunk? could they have shrunk?
V-ing perfect
could I have been shrinking? could you have been shrinking? could he have been shrinking? could we have been shrinking? could you have been shrinking? could they have been shrinking?
Interro-negative form
Simple form
couldn't I shrink? couldn't you shrink? couldn't he shrink? couldn't we shrink? couldn't you shrink? couldn't they shrink?
V-ing form
couldn't I be shrinking? couldn't you be shrinking? couldn't he be shrinking? couldn't we be shrinking? couldn't you be shrinking? couldn't they be shrinking?
Perfect
couldn't I have shrunk? couldn't you have shrunk? couldn't he have shrunk? couldn't we have shrunk? couldn't you have shrunk? couldn't they have shrunk?
V-ing perfect
couldn't I have been shrinking? couldn't you have been shrinking? couldn't he have been shrinking? couldn't we have been shrinking? couldn't you have been shrinking? couldn't they have been shrinking?