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