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