I could perfect you could perfect she could perfect we could perfect you could perfect they could perfect
V-ing form
I could be perfecting you could be perfecting she could be perfecting we could be perfecting you could be perfecting they could be perfecting
Perfect
I could have perfected you could have perfected she could have perfected we could have perfected you could have perfected they could have perfected
V-ing perfect
I could have been perfecting you could have been perfecting she could have been perfecting we could have been perfecting you could have been perfecting they could have been perfecting
Negation
Simple form
I couldn't perfect you couldn't perfect she couldn't perfect we couldn't perfect you couldn't perfect they couldn't perfect
V-ing form
I couldn't be perfecting you couldn't be perfecting she couldn't be perfecting we couldn't be perfecting you couldn't be perfecting they couldn't be perfecting
Perfect
I couldn't have perfected you couldn't have perfected she couldn't have perfected we couldn't have perfected you couldn't have perfected they couldn't have perfected
V-ing perfect
I couldn't have been perfecting you couldn't have been perfecting she couldn't have been perfecting we couldn't have been perfecting you couldn't have been perfecting they couldn't have been perfecting
Interrogative form
Simple form
could I perfect? could you perfect? could she perfect? could we perfect? could you perfect? could they perfect?
V-ing form
could I be perfecting? could you be perfecting? could she be perfecting? could we be perfecting? could you be perfecting? could they be perfecting?
Perfect
could I have perfected? could you have perfected? could she have perfected? could we have perfected? could you have perfected? could they have perfected?
V-ing perfect
could I have been perfecting? could you have been perfecting? could she have been perfecting? could we have been perfecting? could you have been perfecting? could they have been perfecting?
Interro-negative form
Simple form
couldn't I perfect? couldn't you perfect? couldn't she perfect? couldn't we perfect? couldn't you perfect? couldn't they perfect?
V-ing form
couldn't I be perfecting? couldn't you be perfecting? couldn't she be perfecting? couldn't we be perfecting? couldn't you be perfecting? couldn't they be perfecting?
Perfect
couldn't I have perfected? couldn't you have perfected? couldn't she have perfected? couldn't we have perfected? couldn't you have perfected? couldn't they have perfected?
V-ing perfect
couldn't I have been perfecting? couldn't you have been perfecting? couldn't she have been perfecting? couldn't we have been perfecting? couldn't you have been perfecting? couldn't they have been perfecting?