could billboard
Regular verb: billboard - billboarded- billboarded

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could billboard
you could billboard
she could billboard
we could billboard
you could billboard
they could billboard 	I could be billboarding
you could be billboarding
she could be billboarding
we could be billboarding
you could be billboarding
they could be billboarding	I could have billboarded
you could have billboarded
she could have billboarded
we could have billboarded
you could have billboarded
they could have billboarded	I could have been billboarding
you could have been billboarding
she could have been billboarding
we could have been billboarding
you could have been billboarding
they could have been billboarding	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't billboard
you couldn't billboard
she couldn't billboard
we couldn't billboard
you couldn't billboard
they couldn't billboard 	I couldn't be billboarding
you couldn't be billboarding
she couldn't be billboarding
we couldn't be billboarding
you couldn't be billboarding
they couldn't be billboarding	I couldn't have billboarded
you couldn't have billboarded
she couldn't have billboarded
we couldn't have billboarded
you couldn't have billboarded
they couldn't have billboarded	I couldn't have been billboarding
you couldn't have been billboarding
she couldn't have been billboarding
we couldn't have been billboarding
you couldn't have been billboarding
they couldn't have been billboarding	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I billboard?
could you billboard?
could she billboard?
could we billboard?
could you billboard?
could they billboard? 	could I be billboarding?
could you be billboarding?
could she be billboarding?
could we be billboarding?
could you be billboarding?
could they be billboarding? 	could I have billboarded?
could you have billboarded?
could she have billboarded?
could we have billboarded?
could you have billboarded?
could they have billboarded? 	could I have been billboarding?
could you have been billboarding?
could she have been billboarding?
could we have been billboarding?
could you have been billboarding?
could they have been billboarding? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I billboard?
couldn't you billboard?
couldn't she billboard?
couldn't we billboard?
couldn't you billboard?
couldn't they billboard? 	couldn't I be billboarding?
couldn't you be billboarding?
couldn't she be billboarding?
couldn't we be billboarding?
couldn't you be billboarding?
couldn't they be billboarding? 	couldn't I have billboarded?
couldn't you have billboarded?
couldn't she have billboarded?
couldn't we have billboarded?
couldn't you have billboarded?
couldn't they have billboarded? 	couldn't I have been billboarding?
couldn't you have been billboarding?
couldn't she have been billboarding?
couldn't we have been billboarding?
couldn't you have been billboarding?
couldn't they have been billboarding?