could postfix
Regular verb: postfix - postfixed- postfixed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could postfix
you could postfix
he could postfix
we could postfix
you could postfix
they could postfix 	I could be postfixing
you could be postfixing
he could be postfixing
we could be postfixing
you could be postfixing
they could be postfixing	I could have postfixed
you could have postfixed
he could have postfixed
we could have postfixed
you could have postfixed
they could have postfixed	I could have been postfixing
you could have been postfixing
he could have been postfixing
we could have been postfixing
you could have been postfixing
they could have been postfixing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't postfix
you couldn't postfix
he couldn't postfix
we couldn't postfix
you couldn't postfix
they couldn't postfix 	I couldn't be postfixing
you couldn't be postfixing
he couldn't be postfixing
we couldn't be postfixing
you couldn't be postfixing
they couldn't be postfixing	I couldn't have postfixed
you couldn't have postfixed
he couldn't have postfixed
we couldn't have postfixed
you couldn't have postfixed
they couldn't have postfixed	I couldn't have been postfixing
you couldn't have been postfixing
he couldn't have been postfixing
we couldn't have been postfixing
you couldn't have been postfixing
they couldn't have been postfixing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I postfix?
could you postfix?
could he postfix?
could we postfix?
could you postfix?
could they postfix? 	could I be postfixing?
could you be postfixing?
could he be postfixing?
could we be postfixing?
could you be postfixing?
could they be postfixing? 	could I have postfixed?
could you have postfixed?
could he have postfixed?
could we have postfixed?
could you have postfixed?
could they have postfixed? 	could I have been postfixing?
could you have been postfixing?
could he have been postfixing?
could we have been postfixing?
could you have been postfixing?
could they have been postfixing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I postfix?
couldn't you postfix?
couldn't he postfix?
couldn't we postfix?
couldn't you postfix?
couldn't they postfix? 	couldn't I be postfixing?
couldn't you be postfixing?
couldn't he be postfixing?
couldn't we be postfixing?
couldn't you be postfixing?
couldn't they be postfixing? 	couldn't I have postfixed?
couldn't you have postfixed?
couldn't he have postfixed?
couldn't we have postfixed?
couldn't you have postfixed?
couldn't they have postfixed? 	couldn't I have been postfixing?
couldn't you have been postfixing?
couldn't he have been postfixing?
couldn't we have been postfixing?
couldn't you have been postfixing?
couldn't they have been postfixing?