Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could end end you could end end he could end end we could end end you could end end they could end end
V-ing form
I could be end ending you could be end ending he could be end ending we could be end ending you could be end ending they could be end ending
Perfect
I could have end ended you could have end ended he could have end ended we could have end ended you could have end ended they could have end ended
V-ing perfect
I could have been end ending you could have been end ending he could have been end ending we could have been end ending you could have been end ending they could have been end ending
Negation
Simple form
I could not end end you could not end end he could not end end we could not end end you could not end end they could not end end
V-ing form
I could not be end ending you could not be end ending he could not be end ending we could not be end ending you could not be end ending they could not be end ending
Perfect
I could not have end ended you could not have end ended he could not have end ended we could not have end ended you could not have end ended they could not have end ended
V-ing perfect
I could not have been end ending you could not have been end ending he could not have been end ending we could not have been end ending you could not have been end ending they could not have been end ending
Interrogative form
Simple form
could I end end? could you end end? could he end end? could we end end? could you end end? could they end end?
V-ing form
could I be end ending? could you be end ending? could he be end ending? could we be end ending? could you be end ending? could they be end ending?
Perfect
could I have end ended? could you have end ended? could he have end ended? could we have end ended? could you have end ended? could they have end ended?
V-ing perfect
could I have been end ending? could you have been end ending? could he have been end ending? could we have been end ending? could you have been end ending? could they have been end ending?
Interro-negative form
Simple form
could I not end end? could you not end end? could he not end end? could we not end end? could you not end end? could they not end end?
V-ing form
could I not be end ending? could you not be end ending? could he not be end ending? could we not be end ending? could you not be end ending? could they not be end ending?
Perfect
could I not have end ended? could you not have end ended? could he not have end ended? could we not have end ended? could you not have end ended? could they not have end ended?
V-ing perfect
could I not have been end ending? could you not have been end ending? could he not have been end ending? could we not have been end ending? could you not have been end ending? could they not have been end ending?