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