English verb conjugation
COULD PERSEVERE

Regular verb: persevere - persevered - persevered

Affirmation

Simple form	V-ing form
I could persevere you could persevere he could persevere we could persevere you could persevere they could persevere	I could be persevering you could be persevering he could be persevering we could be persevering you could be persevering they could be persevering
Perfect	V-ing perfect
I could have persevered you could have persevered he could have persevered we could have persevered you could have persevered they could have persevered	I could have been persevering you could have been persevering he could have been persevering we could have been persevering you could have been persevering they could have been persevering

Negation

Simple form	V-ing form
I could not persevere you could not persevere he could not persevere we could not persevere you could not persevere they could not persevere	I could not be persevering you could not be persevering he could not be persevering we could not be persevering you could not be persevering they could not be persevering
Perfect	V-ing perfect
I could not have persevered you could not have persevered he could not have persevered we could not have persevered you could not have persevered they could not have persevered	I could not have been persevering you could not have been persevering he could not have been persevering we could not have been persevering you could not have been persevering they could not have been persevering

Interrogative form

Simple form	V-ing form
could I persevere? could you persevere? could he persevere? could we persevere? could you persevere? could they persevere?	could I be persevering? could you be persevering? could he be persevering? could we be persevering? could you be persevering? could they be persevering?
Perfect	V-ing perfect
could I have persevered? could you have persevered? could he have persevered? could we have persevered? could you have persevered? could they have persevered?	could I have been persevering? could you have been persevering? could he have been persevering? could we have been persevering? could you have been persevering? could they have been persevering?

Interro-negative form

Simple form	V-ing form
could I not persevere? could you not persevere? could he not persevere? could we not persevere? could you not persevere? could they not persevere?	could I not be persevering? could you not be persevering? could he not be persevering? could we not be persevering? could you not be persevering? could they not be persevering?
Perfect	V-ing perfect
could I not have persevered? could you not have persevered? could he not have persevered? could we not have persevered? could you not have persevered? could they not have persevered?	could I not have been persevering? could you not have been persevering? could he not have been persevering? could we not have been persevering? could you not have been persevering? could they not have been persevering?