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