I could shelter you could shelter she could shelter we could shelter you could shelter they could shelter
V-ing form
I could be sheltering you could be sheltering she could be sheltering we could be sheltering you could be sheltering they could be sheltering
Perfect
I could have sheltered you could have sheltered she could have sheltered we could have sheltered you could have sheltered they could have sheltered
V-ing perfect
I could have been sheltering you could have been sheltering she could have been sheltering we could have been sheltering you could have been sheltering they could have been sheltering
Negation
Simple form
I could not shelter you could not shelter she could not shelter we could not shelter you could not shelter they could not shelter
V-ing form
I could not be sheltering you could not be sheltering she could not be sheltering we could not be sheltering you could not be sheltering they could not be sheltering
Perfect
I could not have sheltered you could not have sheltered she could not have sheltered we could not have sheltered you could not have sheltered they could not have sheltered
V-ing perfect
I could not have been sheltering you could not have been sheltering she could not have been sheltering we could not have been sheltering you could not have been sheltering they could not have been sheltering
Interrogative form
Simple form
could I shelter? could you shelter? could she shelter? could we shelter? could you shelter? could they shelter?
V-ing form
could I be sheltering? could you be sheltering? could she be sheltering? could we be sheltering? could you be sheltering? could they be sheltering?
Perfect
could I have sheltered? could you have sheltered? could she have sheltered? could we have sheltered? could you have sheltered? could they have sheltered?
V-ing perfect
could I have been sheltering? could you have been sheltering? could she have been sheltering? could we have been sheltering? could you have been sheltering? could they have been sheltering?
Interro-negative form
Simple form
could I not shelter? could you not shelter? could she not shelter? could we not shelter? could you not shelter? could they not shelter?
V-ing form
could I not be sheltering? could you not be sheltering? could she not be sheltering? could we not be sheltering? could you not be sheltering? could they not be sheltering?
Perfect
could I not have sheltered? could you not have sheltered? could she not have sheltered? could we not have sheltered? could you not have sheltered? could they not have sheltered?
V-ing perfect
could I not have been sheltering? could you not have been sheltering? could she not have been sheltering? could we not have been sheltering? could you not have been sheltering? could they not have been sheltering?