I could access you could access he could access we could access you could access they could access
V-ing form
I could be accessing you could be accessing he could be accessing we could be accessing you could be accessing they could be accessing
Perfect
I could have accessed you could have accessed he could have accessed we could have accessed you could have accessed they could have accessed
V-ing perfect
I could have been accessing you could have been accessing he could have been accessing we could have been accessing you could have been accessing they could have been accessing
Negation
Simple form
I could not access you could not access he could not access we could not access you could not access they could not access
V-ing form
I could not be accessing you could not be accessing he could not be accessing we could not be accessing you could not be accessing they could not be accessing
Perfect
I could not have accessed you could not have accessed he could not have accessed we could not have accessed you could not have accessed they could not have accessed
V-ing perfect
I could not have been accessing you could not have been accessing he could not have been accessing we could not have been accessing you could not have been accessing they could not have been accessing
Interrogative form
Simple form
could I access? could you access? could he access? could we access? could you access? could they access?
V-ing form
could I be accessing? could you be accessing? could he be accessing? could we be accessing? could you be accessing? could they be accessing?
Perfect
could I have accessed? could you have accessed? could he have accessed? could we have accessed? could you have accessed? could they have accessed?
V-ing perfect
could I have been accessing? could you have been accessing? could he have been accessing? could we have been accessing? could you have been accessing? could they have been accessing?
Interro-negative form
Simple form
could I not access? could you not access? could he not access? could we not access? could you not access? could they not access?
V-ing form
could I not be accessing? could you not be accessing? could he not be accessing? could we not be accessing? could you not be accessing? could they not be accessing?
Perfect
could I not have accessed? could you not have accessed? could he not have accessed? could we not have accessed? could you not have accessed? could they not have accessed?
V-ing perfect
could I not have been accessing? could you not have been accessing? could he not have been accessing? could we not have been accessing? could you not have been accessing? could they not have been accessing?