could crib
Regular verb: crib - cribbed- cribbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could crib
you could crib
she could crib
we could crib
you could crib
they could crib 	I could be cribbing
you could be cribbing
she could be cribbing
we could be cribbing
you could be cribbing
they could be cribbing	I could have cribbed
you could have cribbed
she could have cribbed
we could have cribbed
you could have cribbed
they could have cribbed	I could have been cribbing
you could have been cribbing
she could have been cribbing
we could have been cribbing
you could have been cribbing
they could have been cribbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't crib
you couldn't crib
she couldn't crib
we couldn't crib
you couldn't crib
they couldn't crib 	I couldn't be cribbing
you couldn't be cribbing
she couldn't be cribbing
we couldn't be cribbing
you couldn't be cribbing
they couldn't be cribbing	I couldn't have cribbed
you couldn't have cribbed
she couldn't have cribbed
we couldn't have cribbed
you couldn't have cribbed
they couldn't have cribbed	I couldn't have been cribbing
you couldn't have been cribbing
she couldn't have been cribbing
we couldn't have been cribbing
you couldn't have been cribbing
they couldn't have been cribbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I crib?
could you crib?
could she crib?
could we crib?
could you crib?
could they crib? 	could I be cribbing?
could you be cribbing?
could she be cribbing?
could we be cribbing?
could you be cribbing?
could they be cribbing? 	could I have cribbed?
could you have cribbed?
could she have cribbed?
could we have cribbed?
could you have cribbed?
could they have cribbed? 	could I have been cribbing?
could you have been cribbing?
could she have been cribbing?
could we have been cribbing?
could you have been cribbing?
could they have been cribbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I crib?
couldn't you crib?
couldn't she crib?
couldn't we crib?
couldn't you crib?
couldn't they crib? 	couldn't I be cribbing?
couldn't you be cribbing?
couldn't she be cribbing?
couldn't we be cribbing?
couldn't you be cribbing?
couldn't they be cribbing? 	couldn't I have cribbed?
couldn't you have cribbed?
couldn't she have cribbed?
couldn't we have cribbed?
couldn't you have cribbed?
couldn't they have cribbed? 	couldn't I have been cribbing?
couldn't you have been cribbing?
couldn't she have been cribbing?
couldn't we have been cribbing?
couldn't you have been cribbing?
couldn't they have been cribbing?