could gibber
Regular verb: gibber - gibbered- gibbered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could gibber
you could gibber
he could gibber
we could gibber
you could gibber
they could gibber 	I could be gibbering
you could be gibbering
he could be gibbering
we could be gibbering
you could be gibbering
they could be gibbering	I could have gibbered
you could have gibbered
he could have gibbered
we could have gibbered
you could have gibbered
they could have gibbered	I could have been gibbering
you could have been gibbering
he could have been gibbering
we could have been gibbering
you could have been gibbering
they could have been gibbering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't gibber
you couldn't gibber
he couldn't gibber
we couldn't gibber
you couldn't gibber
they couldn't gibber 	I couldn't be gibbering
you couldn't be gibbering
he couldn't be gibbering
we couldn't be gibbering
you couldn't be gibbering
they couldn't be gibbering	I couldn't have gibbered
you couldn't have gibbered
he couldn't have gibbered
we couldn't have gibbered
you couldn't have gibbered
they couldn't have gibbered	I couldn't have been gibbering
you couldn't have been gibbering
he couldn't have been gibbering
we couldn't have been gibbering
you couldn't have been gibbering
they couldn't have been gibbering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I gibber?
could you gibber?
could he gibber?
could we gibber?
could you gibber?
could they gibber? 	could I be gibbering?
could you be gibbering?
could he be gibbering?
could we be gibbering?
could you be gibbering?
could they be gibbering? 	could I have gibbered?
could you have gibbered?
could he have gibbered?
could we have gibbered?
could you have gibbered?
could they have gibbered? 	could I have been gibbering?
could you have been gibbering?
could he have been gibbering?
could we have been gibbering?
could you have been gibbering?
could they have been gibbering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I gibber?
couldn't you gibber?
couldn't he gibber?
couldn't we gibber?
couldn't you gibber?
couldn't they gibber? 	couldn't I be gibbering?
couldn't you be gibbering?
couldn't he be gibbering?
couldn't we be gibbering?
couldn't you be gibbering?
couldn't they be gibbering? 	couldn't I have gibbered?
couldn't you have gibbered?
couldn't he have gibbered?
couldn't we have gibbered?
couldn't you have gibbered?
couldn't they have gibbered? 	couldn't I have been gibbering?
couldn't you have been gibbering?
couldn't he have been gibbering?
couldn't we have been gibbering?
couldn't you have been gibbering?
couldn't they have been gibbering?