I could bank you could bank she could bank we could bank you could bank they could bank
V-ing form
I could be banking you could be banking she could be banking we could be banking you could be banking they could be banking
Perfect
I could have banked you could have banked she could have banked we could have banked you could have banked they could have banked
V-ing perfect
I could have been banking you could have been banking she could have been banking we could have been banking you could have been banking they could have been banking
Negation
Simple form
I couldn't bank you couldn't bank she couldn't bank we couldn't bank you couldn't bank they couldn't bank
V-ing form
I couldn't be banking you couldn't be banking she couldn't be banking we couldn't be banking you couldn't be banking they couldn't be banking
Perfect
I couldn't have banked you couldn't have banked she couldn't have banked we couldn't have banked you couldn't have banked they couldn't have banked
V-ing perfect
I couldn't have been banking you couldn't have been banking she couldn't have been banking we couldn't have been banking you couldn't have been banking they couldn't have been banking
Interrogative form
Simple form
could I bank? could you bank? could she bank? could we bank? could you bank? could they bank?
V-ing form
could I be banking? could you be banking? could she be banking? could we be banking? could you be banking? could they be banking?
Perfect
could I have banked? could you have banked? could she have banked? could we have banked? could you have banked? could they have banked?
V-ing perfect
could I have been banking? could you have been banking? could she have been banking? could we have been banking? could you have been banking? could they have been banking?
Interro-negative form
Simple form
couldn't I bank? couldn't you bank? couldn't she bank? couldn't we bank? couldn't you bank? couldn't they bank?
V-ing form
couldn't I be banking? couldn't you be banking? couldn't she be banking? couldn't we be banking? couldn't you be banking? couldn't they be banking?
Perfect
couldn't I have banked? couldn't you have banked? couldn't she have banked? couldn't we have banked? couldn't you have banked? couldn't they have banked?
V-ing perfect
couldn't I have been banking? couldn't you have been banking? couldn't she have been banking? couldn't we have been banking? couldn't you have been banking? couldn't they have been banking?