could chirrup
Regular verb: chirrup - chirruped- chirruped

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could chirrup
you could chirrup
he could chirrup
we could chirrup
you could chirrup
they could chirrup 	I could be chirruping
you could be chirruping
he could be chirruping
we could be chirruping
you could be chirruping
they could be chirruping	I could have chirruped
you could have chirruped
he could have chirruped
we could have chirruped
you could have chirruped
they could have chirruped	I could have been chirruping
you could have been chirruping
he could have been chirruping
we could have been chirruping
you could have been chirruping
they could have been chirruping	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't chirrup
you couldn't chirrup
he couldn't chirrup
we couldn't chirrup
you couldn't chirrup
they couldn't chirrup 	I couldn't be chirruping
you couldn't be chirruping
he couldn't be chirruping
we couldn't be chirruping
you couldn't be chirruping
they couldn't be chirruping	I couldn't have chirruped
you couldn't have chirruped
he couldn't have chirruped
we couldn't have chirruped
you couldn't have chirruped
they couldn't have chirruped	I couldn't have been chirruping
you couldn't have been chirruping
he couldn't have been chirruping
we couldn't have been chirruping
you couldn't have been chirruping
they couldn't have been chirruping	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I chirrup?
could you chirrup?
could he chirrup?
could we chirrup?
could you chirrup?
could they chirrup? 	could I be chirruping?
could you be chirruping?
could he be chirruping?
could we be chirruping?
could you be chirruping?
could they be chirruping? 	could I have chirruped?
could you have chirruped?
could he have chirruped?
could we have chirruped?
could you have chirruped?
could they have chirruped? 	could I have been chirruping?
could you have been chirruping?
could he have been chirruping?
could we have been chirruping?
could you have been chirruping?
could they have been chirruping? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I chirrup?
couldn't you chirrup?
couldn't he chirrup?
couldn't we chirrup?
couldn't you chirrup?
couldn't they chirrup? 	couldn't I be chirruping?
couldn't you be chirruping?
couldn't he be chirruping?
couldn't we be chirruping?
couldn't you be chirruping?
couldn't they be chirruping? 	couldn't I have chirruped?
couldn't you have chirruped?
couldn't he have chirruped?
couldn't we have chirruped?
couldn't you have chirruped?
couldn't they have chirruped? 	couldn't I have been chirruping?
couldn't you have been chirruping?
couldn't he have been chirruping?
couldn't we have been chirruping?
couldn't you have been chirruping?
couldn't they have been chirruping?