could flicker
Regular verb: flicker - flickered- flickered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could flicker
you could flicker
he could flicker
we could flicker
you could flicker
they could flicker 	I could be flickering
you could be flickering
he could be flickering
we could be flickering
you could be flickering
they could be flickering	I could have flickered
you could have flickered
he could have flickered
we could have flickered
you could have flickered
they could have flickered	I could have been flickering
you could have been flickering
he could have been flickering
we could have been flickering
you could have been flickering
they could have been flickering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't flicker
you couldn't flicker
he couldn't flicker
we couldn't flicker
you couldn't flicker
they couldn't flicker 	I couldn't be flickering
you couldn't be flickering
he couldn't be flickering
we couldn't be flickering
you couldn't be flickering
they couldn't be flickering	I couldn't have flickered
you couldn't have flickered
he couldn't have flickered
we couldn't have flickered
you couldn't have flickered
they couldn't have flickered	I couldn't have been flickering
you couldn't have been flickering
he couldn't have been flickering
we couldn't have been flickering
you couldn't have been flickering
they couldn't have been flickering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I flicker?
could you flicker?
could he flicker?
could we flicker?
could you flicker?
could they flicker? 	could I be flickering?
could you be flickering?
could he be flickering?
could we be flickering?
could you be flickering?
could they be flickering? 	could I have flickered?
could you have flickered?
could he have flickered?
could we have flickered?
could you have flickered?
could they have flickered? 	could I have been flickering?
could you have been flickering?
could he have been flickering?
could we have been flickering?
could you have been flickering?
could they have been flickering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I flicker?
couldn't you flicker?
couldn't he flicker?
couldn't we flicker?
couldn't you flicker?
couldn't they flicker? 	couldn't I be flickering?
couldn't you be flickering?
couldn't he be flickering?
couldn't we be flickering?
couldn't you be flickering?
couldn't they be flickering? 	couldn't I have flickered?
couldn't you have flickered?
couldn't he have flickered?
couldn't we have flickered?
couldn't you have flickered?
couldn't they have flickered? 	couldn't I have been flickering?
couldn't you have been flickering?
couldn't he have been flickering?
couldn't we have been flickering?
couldn't you have been flickering?
couldn't they have been flickering?