could persevere
Regular verb: persevere - persevered- persevered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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	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 	Perfect 	V-ing perfect 	
I couldn't persevere
you couldn't persevere
he couldn't persevere
we couldn't persevere
you couldn't persevere
they couldn't persevere 	I couldn't be persevering
you couldn't be persevering
he couldn't be persevering
we couldn't be persevering
you couldn't be persevering
they couldn't be persevering	I couldn't have persevered
you couldn't have persevered
he couldn't have persevered
we couldn't have persevered
you couldn't have persevered
they couldn't have persevered	I couldn't have been persevering
you couldn't have been persevering
he couldn't have been persevering
we couldn't have been persevering
you couldn't have been persevering
they couldn't have been persevering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
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? 	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 	Perfect 	V-ing perfect 	
couldn't I persevere?
couldn't you persevere?
couldn't he persevere?
couldn't we persevere?
couldn't you persevere?
couldn't they persevere? 	couldn't I be persevering?
couldn't you be persevering?
couldn't he be persevering?
couldn't we be persevering?
couldn't you be persevering?
couldn't they be persevering? 	couldn't I have persevered?
couldn't you have persevered?
couldn't he have persevered?
couldn't we have persevered?
couldn't you have persevered?
couldn't they have persevered? 	couldn't I have been persevering?
couldn't you have been persevering?
couldn't he have been persevering?
couldn't we have been persevering?
couldn't you have been persevering?
couldn't they have been persevering?