could burrow
Regular verb: burrow - burrowed- burrowed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could burrow
you could burrow
she could burrow
we could burrow
you could burrow
they could burrow 	I could be burrowing
you could be burrowing
she could be burrowing
we could be burrowing
you could be burrowing
they could be burrowing	I could have burrowed
you could have burrowed
she could have burrowed
we could have burrowed
you could have burrowed
they could have burrowed	I could have been burrowing
you could have been burrowing
she could have been burrowing
we could have been burrowing
you could have been burrowing
they could have been burrowing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not burrow
you could not burrow
she could not burrow
we could not burrow
you could not burrow
they could not burrow 	I could not be burrowing
you could not be burrowing
she could not be burrowing
we could not be burrowing
you could not be burrowing
they could not be burrowing	I could not have burrowed
you could not have burrowed
she could not have burrowed
we could not have burrowed
you could not have burrowed
they could not have burrowed	I could not have been burrowing
you could not have been burrowing
she could not have been burrowing
we could not have been burrowing
you could not have been burrowing
they could not have been burrowing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I burrow?
could you burrow?
could she burrow?
could we burrow?
could you burrow?
could they burrow? 	could I be burrowing?
could you be burrowing?
could she be burrowing?
could we be burrowing?
could you be burrowing?
could they be burrowing? 	could I have burrowed?
could you have burrowed?
could she have burrowed?
could we have burrowed?
could you have burrowed?
could they have burrowed? 	could I have been burrowing?
could you have been burrowing?
could she have been burrowing?
could we have been burrowing?
could you have been burrowing?
could they have been burrowing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not burrow?
could you not burrow?
could she not burrow?
could we not burrow?
could you not burrow?
could they not burrow? 	could I not be burrowing?
could you not be burrowing?
could she not be burrowing?
could we not be burrowing?
could you not be burrowing?
could they not be burrowing? 	could I not have burrowed?
could you not have burrowed?
could she not have burrowed?
could we not have burrowed?
could you not have burrowed?
could they not have burrowed? 	could I not have been burrowing?
could you not have been burrowing?
could she not have been burrowing?
could we not have been burrowing?
could you not have been burrowing?
could they not have been burrowing?