could tab
Regular verb: tab - tabed- tabed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tab
you could tab
she could tab
we could tab
you could tab
they could tab 	I could be tabing
you could be tabing
she could be tabing
we could be tabing
you could be tabing
they could be tabing	I could have tabed
you could have tabed
she could have tabed
we could have tabed
you could have tabed
they could have tabed	I could have been tabing
you could have been tabing
she could have been tabing
we could have been tabing
you could have been tabing
they could have been tabing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't tab
you couldn't tab
she couldn't tab
we couldn't tab
you couldn't tab
they couldn't tab 	I couldn't be tabing
you couldn't be tabing
she couldn't be tabing
we couldn't be tabing
you couldn't be tabing
they couldn't be tabing	I couldn't have tabed
you couldn't have tabed
she couldn't have tabed
we couldn't have tabed
you couldn't have tabed
they couldn't have tabed	I couldn't have been tabing
you couldn't have been tabing
she couldn't have been tabing
we couldn't have been tabing
you couldn't have been tabing
they couldn't have been tabing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tab?
could you tab?
could she tab?
could we tab?
could you tab?
could they tab? 	could I be tabing?
could you be tabing?
could she be tabing?
could we be tabing?
could you be tabing?
could they be tabing? 	could I have tabed?
could you have tabed?
could she have tabed?
could we have tabed?
could you have tabed?
could they have tabed? 	could I have been tabing?
could you have been tabing?
could she have been tabing?
could we have been tabing?
could you have been tabing?
could they have been tabing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I tab?
couldn't you tab?
couldn't she tab?
couldn't we tab?
couldn't you tab?
couldn't they tab? 	couldn't I be tabing?
couldn't you be tabing?
couldn't she be tabing?
couldn't we be tabing?
couldn't you be tabing?
couldn't they be tabing? 	couldn't I have tabed?
couldn't you have tabed?
couldn't she have tabed?
couldn't we have tabed?
couldn't you have tabed?
couldn't they have tabed? 	couldn't I have been tabing?
couldn't you have been tabing?
couldn't she have been tabing?
couldn't we have been tabing?
couldn't you have been tabing?
couldn't they have been tabing?