I could arc you could arc he could arc we could arc you could arc they could arc
V-ing form
I could be arcing you could be arcing he could be arcing we could be arcing you could be arcing they could be arcing
Perfect
I could have arced you could have arced he could have arced we could have arced you could have arced they could have arced
V-ing perfect
I could have been arcing you could have been arcing he could have been arcing we could have been arcing you could have been arcing they could have been arcing
Negation
Simple form
I could not arc you could not arc he could not arc we could not arc you could not arc they could not arc
V-ing form
I could not be arcing you could not be arcing he could not be arcing we could not be arcing you could not be arcing they could not be arcing
Perfect
I could not have arced you could not have arced he could not have arced we could not have arced you could not have arced they could not have arced
V-ing perfect
I could not have been arcing you could not have been arcing he could not have been arcing we could not have been arcing you could not have been arcing they could not have been arcing
Interrogative form
Simple form
could I arc? could you arc? could he arc? could we arc? could you arc? could they arc?
V-ing form
could I be arcing? could you be arcing? could he be arcing? could we be arcing? could you be arcing? could they be arcing?
Perfect
could I have arced? could you have arced? could he have arced? could we have arced? could you have arced? could they have arced?
V-ing perfect
could I have been arcing? could you have been arcing? could he have been arcing? could we have been arcing? could you have been arcing? could they have been arcing?
Interro-negative form
Simple form
could I not arc? could you not arc? could he not arc? could we not arc? could you not arc? could they not arc?
V-ing form
could I not be arcing? could you not be arcing? could he not be arcing? could we not be arcing? could you not be arcing? could they not be arcing?
Perfect
could I not have arced? could you not have arced? could he not have arced? could we not have arced? could you not have arced? could they not have arced?
V-ing perfect
could I not have been arcing? could you not have been arcing? could he not have been arcing? could we not have been arcing? could you not have been arcing? could they not have been arcing?