could bob
Regular verb: bob - bobbed- bobbed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could bob
you could bob
he could bob
we could bob
you could bob
they could bob 	I could be bobbing
you could be bobbing
he could be bobbing
we could be bobbing
you could be bobbing
they could be bobbing	I could have bobbed
you could have bobbed
he could have bobbed
we could have bobbed
you could have bobbed
they could have bobbed	I could have been bobbing
you could have been bobbing
he could have been bobbing
we could have been bobbing
you could have been bobbing
they could have been bobbing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't bob
you couldn't bob
he couldn't bob
we couldn't bob
you couldn't bob
they couldn't bob 	I couldn't be bobbing
you couldn't be bobbing
he couldn't be bobbing
we couldn't be bobbing
you couldn't be bobbing
they couldn't be bobbing	I couldn't have bobbed
you couldn't have bobbed
he couldn't have bobbed
we couldn't have bobbed
you couldn't have bobbed
they couldn't have bobbed	I couldn't have been bobbing
you couldn't have been bobbing
he couldn't have been bobbing
we couldn't have been bobbing
you couldn't have been bobbing
they couldn't have been bobbing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I bob?
could you bob?
could he bob?
could we bob?
could you bob?
could they bob? 	could I be bobbing?
could you be bobbing?
could he be bobbing?
could we be bobbing?
could you be bobbing?
could they be bobbing? 	could I have bobbed?
could you have bobbed?
could he have bobbed?
could we have bobbed?
could you have bobbed?
could they have bobbed? 	could I have been bobbing?
could you have been bobbing?
could he have been bobbing?
could we have been bobbing?
could you have been bobbing?
could they have been bobbing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I bob?
couldn't you bob?
couldn't he bob?
couldn't we bob?
couldn't you bob?
couldn't they bob? 	couldn't I be bobbing?
couldn't you be bobbing?
couldn't he be bobbing?
couldn't we be bobbing?
couldn't you be bobbing?
couldn't they be bobbing? 	couldn't I have bobbed?
couldn't you have bobbed?
couldn't he have bobbed?
couldn't we have bobbed?
couldn't you have bobbed?
couldn't they have bobbed? 	couldn't I have been bobbing?
couldn't you have been bobbing?
couldn't he have been bobbing?
couldn't we have been bobbing?
couldn't you have been bobbing?
couldn't they have been bobbing?