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