I could collapse you could collapse he could collapse we could collapse you could collapse they could collapse
Forma com V-ing
I could be collapsing you could be collapsing he could be collapsing we could be collapsing you could be collapsing they could be collapsing
Perfeito
I could have collapsed you could have collapsed he could have collapsed we could have collapsed you could have collapsed they could have collapsed
Perfeito com V-ing
I could have been collapsing you could have been collapsing he could have been collapsing we could have been collapsing you could have been collapsing they could have been collapsing
Negação
Forma simple
I could not collapse you could not collapse he could not collapse we could not collapse you could not collapse they could not collapse
Forma com V-ing
I could not be collapsing you could not be collapsing he could not be collapsing we could not be collapsing you could not be collapsing they could not be collapsing
Perfeito
I could not have collapsed you could not have collapsed he could not have collapsed we could not have collapsed you could not have collapsed they could not have collapsed
Perfeito com V-ing
I could not have been collapsing you could not have been collapsing he could not have been collapsing we could not have been collapsing you could not have been collapsing they could not have been collapsing
Forma interrogativa
Forma simple
could I collapse? could you collapse? could he collapse? could we collapse? could you collapse? could they collapse?
Forma com V-ing
could I be collapsing? could you be collapsing? could he be collapsing? could we be collapsing? could you be collapsing? could they be collapsing?
Perfeito
could I have collapsed? could you have collapsed? could he have collapsed? could we have collapsed? could you have collapsed? could they have collapsed?
Perfeito com V-ing
could I have been collapsing? could you have been collapsing? could he have been collapsing? could we have been collapsing? could you have been collapsing? could they have been collapsing?
Forma interro-Negação
Forma simple
could I not collapse? could you not collapse? could he not collapse? could we not collapse? could you not collapse? could they not collapse?
Forma com V-ing
could I not be collapsing? could you not be collapsing? could he not be collapsing? could we not be collapsing? could you not be collapsing? could they not be collapsing?
Perfeito
could I not have collapsed? could you not have collapsed? could he not have collapsed? could we not have collapsed? could you not have collapsed? could they not have collapsed?
Perfeito com V-ing
could I not have been collapsing? could you not have been collapsing? could he not have been collapsing? could we not have been collapsing? could you not have been collapsing? could they not have been collapsing?