could birch
Regular verb: birch - birched- birched

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could birch
you could birch
he could birch
we could birch
you could birch
they could birch 	I could be birching
you could be birching
he could be birching
we could be birching
you could be birching
they could be birching	I could have birched
you could have birched
he could have birched
we could have birched
you could have birched
they could have birched	I could have been birching
you could have been birching
he could have been birching
we could have been birching
you could have been birching
they could have been birching	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't birch
you couldn't birch
he couldn't birch
we couldn't birch
you couldn't birch
they couldn't birch 	I couldn't be birching
you couldn't be birching
he couldn't be birching
we couldn't be birching
you couldn't be birching
they couldn't be birching	I couldn't have birched
you couldn't have birched
he couldn't have birched
we couldn't have birched
you couldn't have birched
they couldn't have birched	I couldn't have been birching
you couldn't have been birching
he couldn't have been birching
we couldn't have been birching
you couldn't have been birching
they couldn't have been birching	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I birch?
could you birch?
could he birch?
could we birch?
could you birch?
could they birch? 	could I be birching?
could you be birching?
could he be birching?
could we be birching?
could you be birching?
could they be birching? 	could I have birched?
could you have birched?
could he have birched?
could we have birched?
could you have birched?
could they have birched? 	could I have been birching?
could you have been birching?
could he have been birching?
could we have been birching?
could you have been birching?
could they have been birching? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I birch?
couldn't you birch?
couldn't he birch?
couldn't we birch?
couldn't you birch?
couldn't they birch? 	couldn't I be birching?
couldn't you be birching?
couldn't he be birching?
couldn't we be birching?
couldn't you be birching?
couldn't they be birching? 	couldn't I have birched?
couldn't you have birched?
couldn't he have birched?
couldn't we have birched?
couldn't you have birched?
couldn't they have birched? 	couldn't I have been birching?
couldn't you have been birching?
couldn't he have been birching?
couldn't we have been birching?
couldn't you have been birching?
couldn't they have been birching?