I could disagree you could disagree he could disagree we could disagree you could disagree they could disagree
V-ing form
I could be disagreeing you could be disagreeing he could be disagreeing we could be disagreeing you could be disagreeing they could be disagreeing
Perfect
I could have disagreed you could have disagreed he could have disagreed we could have disagreed you could have disagreed they could have disagreed
V-ing perfect
I could have been disagreeing you could have been disagreeing he could have been disagreeing we could have been disagreeing you could have been disagreeing they could have been disagreeing
Negation
Simple form
I could not disagree you could not disagree he could not disagree we could not disagree you could not disagree they could not disagree
V-ing form
I could not be disagreeing you could not be disagreeing he could not be disagreeing we could not be disagreeing you could not be disagreeing they could not be disagreeing
Perfect
I could not have disagreed you could not have disagreed he could not have disagreed we could not have disagreed you could not have disagreed they could not have disagreed
V-ing perfect
I could not have been disagreeing you could not have been disagreeing he could not have been disagreeing we could not have been disagreeing you could not have been disagreeing they could not have been disagreeing
Interrogative form
Simple form
could I disagree? could you disagree? could he disagree? could we disagree? could you disagree? could they disagree?
V-ing form
could I be disagreeing? could you be disagreeing? could he be disagreeing? could we be disagreeing? could you be disagreeing? could they be disagreeing?
Perfect
could I have disagreed? could you have disagreed? could he have disagreed? could we have disagreed? could you have disagreed? could they have disagreed?
V-ing perfect
could I have been disagreeing? could you have been disagreeing? could he have been disagreeing? could we have been disagreeing? could you have been disagreeing? could they have been disagreeing?
Interro-negative form
Simple form
could I not disagree? could you not disagree? could he not disagree? could we not disagree? could you not disagree? could they not disagree?
V-ing form
could I not be disagreeing? could you not be disagreeing? could he not be disagreeing? could we not be disagreeing? could you not be disagreeing? could they not be disagreeing?
Perfect
could I not have disagreed? could you not have disagreed? could he not have disagreed? could we not have disagreed? could you not have disagreed? could they not have disagreed?
V-ing perfect
could I not have been disagreeing? could you not have been disagreeing? could he not have been disagreeing? could we not have been disagreeing? could you not have been disagreeing? could they not have been disagreeing?