I could produce you could produce he could produce we could produce you could produce they could produce
V-ing form
I could be producing you could be producing he could be producing we could be producing you could be producing they could be producing
Perfect
I could have produced you could have produced he could have produced we could have produced you could have produced they could have produced
V-ing perfect
I could have been producing you could have been producing he could have been producing we could have been producing you could have been producing they could have been producing
Negation
Simple form
I could not produce you could not produce he could not produce we could not produce you could not produce they could not produce
V-ing form
I could not be producing you could not be producing he could not be producing we could not be producing you could not be producing they could not be producing
Perfect
I could not have produced you could not have produced he could not have produced we could not have produced you could not have produced they could not have produced
V-ing perfect
I could not have been producing you could not have been producing he could not have been producing we could not have been producing you could not have been producing they could not have been producing
Interrogative form
Simple form
could I produce? could you produce? could he produce? could we produce? could you produce? could they produce?
V-ing form
could I be producing? could you be producing? could he be producing? could we be producing? could you be producing? could they be producing?
Perfect
could I have produced? could you have produced? could he have produced? could we have produced? could you have produced? could they have produced?
V-ing perfect
could I have been producing? could you have been producing? could he have been producing? could we have been producing? could you have been producing? could they have been producing?
Interro-negative form
Simple form
could I not produce? could you not produce? could he not produce? could we not produce? could you not produce? could they not produce?
V-ing form
could I not be producing? could you not be producing? could he not be producing? could we not be producing? could you not be producing? could they not be producing?
Perfect
could I not have produced? could you not have produced? could he not have produced? could we not have produced? could you not have produced? could they not have produced?
V-ing perfect
could I not have been producing? could you not have been producing? could he not have been producing? could we not have been producing? could you not have been producing? could they not have been producing?