I could medicine you could medicine he could medicine we could medicine you could medicine they could medicine
V-ing form
I could be medicining you could be medicining he could be medicining we could be medicining you could be medicining they could be medicining
Perfect
I could have medicined you could have medicined he could have medicined we could have medicined you could have medicined they could have medicined
V-ing perfect
I could have been medicining you could have been medicining he could have been medicining we could have been medicining you could have been medicining they could have been medicining
Negation
Simple form
I could not medicine you could not medicine he could not medicine we could not medicine you could not medicine they could not medicine
V-ing form
I could not be medicining you could not be medicining he could not be medicining we could not be medicining you could not be medicining they could not be medicining
Perfect
I could not have medicined you could not have medicined he could not have medicined we could not have medicined you could not have medicined they could not have medicined
V-ing perfect
I could not have been medicining you could not have been medicining he could not have been medicining we could not have been medicining you could not have been medicining they could not have been medicining
Interrogative form
Simple form
could I medicine? could you medicine? could he medicine? could we medicine? could you medicine? could they medicine?
V-ing form
could I be medicining? could you be medicining? could he be medicining? could we be medicining? could you be medicining? could they be medicining?
Perfect
could I have medicined? could you have medicined? could he have medicined? could we have medicined? could you have medicined? could they have medicined?
V-ing perfect
could I have been medicining? could you have been medicining? could he have been medicining? could we have been medicining? could you have been medicining? could they have been medicining?
Interro-negative form
Simple form
could I not medicine? could you not medicine? could he not medicine? could we not medicine? could you not medicine? could they not medicine?
V-ing form
could I not be medicining? could you not be medicining? could he not be medicining? could we not be medicining? could you not be medicining? could they not be medicining?
Perfect
could I not have medicined? could you not have medicined? could he not have medicined? could we not have medicined? could you not have medicined? could they not have medicined?
V-ing perfect
could I not have been medicining? could you not have been medicining? could he not have been medicining? could we not have been medicining? could you not have been medicining? could they not have been medicining?