I could bank you could bank he could bank we could bank you could bank they could bank
V-ing form
I could be banking you could be banking he could be banking we could be banking you could be banking they could be banking
Perfect
I could have banked you could have banked he 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 he 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 he 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 he 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 he 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 he 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 he bank? could we bank? could you bank? could they bank?
V-ing form
could I be banking? could you be banking? could he be banking? could we be banking? could you be banking? could they be banking?
Perfect
could I have banked? could you have banked? could he 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 he 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 he 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 he 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 he 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 he have been banking? couldn't we have been banking? couldn't you have been banking? couldn't they have been banking?