I could sadden you could sadden he could sadden we could sadden you could sadden they could sadden
V-ing form
I could be saddening you could be saddening he could be saddening we could be saddening you could be saddening they could be saddening
Perfect
I could have saddened you could have saddened he could have saddened we could have saddened you could have saddened they could have saddened
V-ing perfect
I could have been saddening you could have been saddening he could have been saddening we could have been saddening you could have been saddening they could have been saddening
Negation
Simple form
I could not sadden you could not sadden he could not sadden we could not sadden you could not sadden they could not sadden
V-ing form
I could not be saddening you could not be saddening he could not be saddening we could not be saddening you could not be saddening they could not be saddening
Perfect
I could not have saddened you could not have saddened he could not have saddened we could not have saddened you could not have saddened they could not have saddened
V-ing perfect
I could not have been saddening you could not have been saddening he could not have been saddening we could not have been saddening you could not have been saddening they could not have been saddening
Interrogative form
Simple form
could I sadden? could you sadden? could he sadden? could we sadden? could you sadden? could they sadden?
V-ing form
could I be saddening? could you be saddening? could he be saddening? could we be saddening? could you be saddening? could they be saddening?
Perfect
could I have saddened? could you have saddened? could he have saddened? could we have saddened? could you have saddened? could they have saddened?
V-ing perfect
could I have been saddening? could you have been saddening? could he have been saddening? could we have been saddening? could you have been saddening? could they have been saddening?
Interro-negative form
Simple form
could I not sadden? could you not sadden? could he not sadden? could we not sadden? could you not sadden? could they not sadden?
V-ing form
could I not be saddening? could you not be saddening? could he not be saddening? could we not be saddening? could you not be saddening? could they not be saddening?
Perfect
could I not have saddened? could you not have saddened? could he not have saddened? could we not have saddened? could you not have saddened? could they not have saddened?
V-ing perfect
could I not have been saddening? could you not have been saddening? could he not have been saddening? could we not have been saddening? could you not have been saddening? could they not have been saddening?