I could remove you could remove he could remove we could remove you could remove they could remove
V-ing form
I could be removing you could be removing he could be removing we could be removing you could be removing they could be removing
Perfect
I could have removed you could have removed he could have removed we could have removed you could have removed they could have removed
V-ing perfect
I could have been removing you could have been removing he could have been removing we could have been removing you could have been removing they could have been removing
Negation
Simple form
I couldn't remove you couldn't remove he couldn't remove we couldn't remove you couldn't remove they couldn't remove
V-ing form
I couldn't be removing you couldn't be removing he couldn't be removing we couldn't be removing you couldn't be removing they couldn't be removing
Perfect
I couldn't have removed you couldn't have removed he couldn't have removed we couldn't have removed you couldn't have removed they couldn't have removed
V-ing perfect
I couldn't have been removing you couldn't have been removing he couldn't have been removing we couldn't have been removing you couldn't have been removing they couldn't have been removing
Interrogative form
Simple form
could I remove? could you remove? could he remove? could we remove? could you remove? could they remove?
V-ing form
could I be removing? could you be removing? could he be removing? could we be removing? could you be removing? could they be removing?
Perfect
could I have removed? could you have removed? could he have removed? could we have removed? could you have removed? could they have removed?
V-ing perfect
could I have been removing? could you have been removing? could he have been removing? could we have been removing? could you have been removing? could they have been removing?
Interro-negative form
Simple form
couldn't I remove? couldn't you remove? couldn't he remove? couldn't we remove? couldn't you remove? couldn't they remove?
V-ing form
couldn't I be removing? couldn't you be removing? couldn't he be removing? couldn't we be removing? couldn't you be removing? couldn't they be removing?
Perfect
couldn't I have removed? couldn't you have removed? couldn't he have removed? couldn't we have removed? couldn't you have removed? couldn't they have removed?
V-ing perfect
couldn't I have been removing? couldn't you have been removing? couldn't he have been removing? couldn't we have been removing? couldn't you have been removing? couldn't they have been removing?