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 couldn't access you couldn't access he couldn't access we couldn't access you couldn't access they couldn't access
V-ing form
I couldn't be accessing you couldn't be accessing he couldn't be accessing we couldn't be accessing you couldn't be accessing they couldn't be accessing
Perfect
I couldn't have accessed you couldn't have accessed he couldn't have accessed we couldn't have accessed you couldn't have accessed they couldn't have accessed
V-ing perfect
I couldn't have been accessing you couldn't have been accessing he couldn't have been accessing we couldn't have been accessing you couldn't have been accessing they couldn't 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
couldn't I access? couldn't you access? couldn't he access? couldn't we access? couldn't you access? couldn't they access?
V-ing form
couldn't I be accessing? couldn't you be accessing? couldn't he be accessing? couldn't we be accessing? couldn't you be accessing? couldn't they be accessing?
Perfect
couldn't I have accessed? couldn't you have accessed? couldn't he have accessed? couldn't we have accessed? couldn't you have accessed? couldn't they have accessed?
V-ing perfect
couldn't I have been accessing? couldn't you have been accessing? couldn't he have been accessing? couldn't we have been accessing? couldn't you have been accessing? couldn't they have been accessing?