I could sample you could sample she could sample we could sample you could sample they could sample
V-ing form
I could be sampling you could be sampling she could be sampling we could be sampling you could be sampling they could be sampling
Perfect
I could have sampled you could have sampled she could have sampled we could have sampled you could have sampled they could have sampled
V-ing perfect
I could have been sampling you could have been sampling she could have been sampling we could have been sampling you could have been sampling they could have been sampling
Negation
Simple form
I could not sample you could not sample she could not sample we could not sample you could not sample they could not sample
V-ing form
I could not be sampling you could not be sampling she could not be sampling we could not be sampling you could not be sampling they could not be sampling
Perfect
I could not have sampled you could not have sampled she could not have sampled we could not have sampled you could not have sampled they could not have sampled
V-ing perfect
I could not have been sampling you could not have been sampling she could not have been sampling we could not have been sampling you could not have been sampling they could not have been sampling
Interrogative form
Simple form
could I sample? could you sample? could she sample? could we sample? could you sample? could they sample?
V-ing form
could I be sampling? could you be sampling? could she be sampling? could we be sampling? could you be sampling? could they be sampling?
Perfect
could I have sampled? could you have sampled? could she have sampled? could we have sampled? could you have sampled? could they have sampled?
V-ing perfect
could I have been sampling? could you have been sampling? could she have been sampling? could we have been sampling? could you have been sampling? could they have been sampling?
Interro-negative form
Simple form
could I not sample? could you not sample? could she not sample? could we not sample? could you not sample? could they not sample?
V-ing form
could I not be sampling? could you not be sampling? could she not be sampling? could we not be sampling? could you not be sampling? could they not be sampling?
Perfect
could I not have sampled? could you not have sampled? could she not have sampled? could we not have sampled? could you not have sampled? could they not have sampled?
V-ing perfect
could I not have been sampling? could you not have been sampling? could she not have been sampling? could we not have been sampling? could you not have been sampling? could they not have been sampling?