could reason
Regular verb: reason - reasoned- reasoned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could reason
you could reason
he could reason
we could reason
you could reason
they could reason 	I could be reasoning
you could be reasoning
he could be reasoning
we could be reasoning
you could be reasoning
they could be reasoning	I could have reasoned
you could have reasoned
he 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
he 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 could not reason
you could not reason
he could not reason
we could not reason
you could not reason
they could not reason 	I could not be reasoning
you could not be reasoning
he could not be reasoning
we could not be reasoning
you could not be reasoning
they could not be reasoning	I could not have reasoned
you could not have reasoned
he could not have reasoned
we could not have reasoned
you could not have reasoned
they could not have reasoned	I could not have been reasoning
you could not have been reasoning
he could not have been reasoning
we could not have been reasoning
you could not have been reasoning
they could not have been reasoning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I reason?
could you reason?
could he reason?
could we reason?
could you reason?
could they reason? 	could I be reasoning?
could you be reasoning?
could he be reasoning?
could we be reasoning?
could you be reasoning?
could they be reasoning? 	could I have reasoned?
could you have reasoned?
could he 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 he 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 	
could I not reason?
could you not reason?
could he not reason?
could we not reason?
could you not reason?
could they not reason? 	could I not be reasoning?
could you not be reasoning?
could he not be reasoning?
could we not be reasoning?
could you not be reasoning?
could they not be reasoning? 	could I not have reasoned?
could you not have reasoned?
could he not have reasoned?
could we not have reasoned?
could you not have reasoned?
could they not have reasoned? 	could I not have been reasoning?
could you not have been reasoning?
could he not have been reasoning?
could we not have been reasoning?
could you not have been reasoning?
could they not have been reasoning?