could reason
Regular verb: reason - reasoned- reasoned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could reason
you could reason
she could reason
we could reason
you could reason
they could reason 	I could be reasoning
you could be reasoning
she could be reasoning
we could be reasoning
you could be reasoning
they could be reasoning	I could have reasoned
you could have reasoned
she could have reasoned
we could have reasoned
you could have reasoned
they could have reasoned	I could have been reasoning
you could have been reasoning
she could have been reasoning
we could have been reasoning
you could have been reasoning
they could have been reasoning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't reason
you couldn't reason
she couldn't reason
we couldn't reason
you couldn't reason
they couldn't reason 	I couldn't be reasoning
you couldn't be reasoning
she couldn't be reasoning
we couldn't be reasoning
you couldn't be reasoning
they couldn't be reasoning	I couldn't have reasoned
you couldn't have reasoned
she couldn't have reasoned
we couldn't have reasoned
you couldn't have reasoned
they couldn't have reasoned	I couldn't have been reasoning
you couldn't have been reasoning
she couldn't have been reasoning
we couldn't have been reasoning
you couldn't have been reasoning
they couldn't have been reasoning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I reason?
could you reason?
could she reason?
could we reason?
could you reason?
could they reason? 	could I be reasoning?
could you be reasoning?
could she be reasoning?
could we be reasoning?
could you be reasoning?
could they be reasoning? 	could I have reasoned?
could you have reasoned?
could she have reasoned?
could we have reasoned?
could you have reasoned?
could they have reasoned? 	could I have been reasoning?
could you have been reasoning?
could she have been reasoning?
could we have been reasoning?
could you have been reasoning?
could they have been reasoning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I reason?
couldn't you reason?
couldn't she reason?
couldn't we reason?
couldn't you reason?
couldn't they reason? 	couldn't I be reasoning?
couldn't you be reasoning?
couldn't she be reasoning?
couldn't we be reasoning?
couldn't you be reasoning?
couldn't they be reasoning? 	couldn't I have reasoned?
couldn't you have reasoned?
couldn't she have reasoned?
couldn't we have reasoned?
couldn't you have reasoned?
couldn't they have reasoned? 	couldn't I have been reasoning?
couldn't you have been reasoning?
couldn't she have been reasoning?
couldn't we have been reasoning?
couldn't you have been reasoning?
couldn't they have been reasoning?