I could water you could water she could water we could water you could water they could water
V-ing form
I could be watering you could be watering she could be watering we could be watering you could be watering they could be watering
Perfect
I could have watered you could have watered she could have watered we could have watered you could have watered they could have watered
V-ing perfect
I could have been watering you could have been watering she could have been watering we could have been watering you could have been watering they could have been watering
Negation
Simple form
I could not water you could not water she could not water we could not water you could not water they could not water
V-ing form
I could not be watering you could not be watering she could not be watering we could not be watering you could not be watering they could not be watering
Perfect
I could not have watered you could not have watered she could not have watered we could not have watered you could not have watered they could not have watered
V-ing perfect
I could not have been watering you could not have been watering she could not have been watering we could not have been watering you could not have been watering they could not have been watering
Interrogative form
Simple form
could I water? could you water? could she water? could we water? could you water? could they water?
V-ing form
could I be watering? could you be watering? could she be watering? could we be watering? could you be watering? could they be watering?
Perfect
could I have watered? could you have watered? could she have watered? could we have watered? could you have watered? could they have watered?
V-ing perfect
could I have been watering? could you have been watering? could she have been watering? could we have been watering? could you have been watering? could they have been watering?
Interro-negative form
Simple form
could I not water? could you not water? could she not water? could we not water? could you not water? could they not water?
V-ing form
could I not be watering? could you not be watering? could she not be watering? could we not be watering? could you not be watering? could they not be watering?
Perfect
could I not have watered? could you not have watered? could she not have watered? could we not have watered? could you not have watered? could they not have watered?
V-ing perfect
could I not have been watering? could you not have been watering? could she not have been watering? could we not have been watering? could you not have been watering? could they not have been watering?