could calender
Regular verb: calender - calendered- calendered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could calender
you could calender
she could calender
we could calender
you could calender
they could calender 	I could be calendering
you could be calendering
she could be calendering
we could be calendering
you could be calendering
they could be calendering	I could have calendered
you could have calendered
she could have calendered
we could have calendered
you could have calendered
they could have calendered	I could have been calendering
you could have been calendering
she could have been calendering
we could have been calendering
you could have been calendering
they could have been calendering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't calender
you couldn't calender
she couldn't calender
we couldn't calender
you couldn't calender
they couldn't calender 	I couldn't be calendering
you couldn't be calendering
she couldn't be calendering
we couldn't be calendering
you couldn't be calendering
they couldn't be calendering	I couldn't have calendered
you couldn't have calendered
she couldn't have calendered
we couldn't have calendered
you couldn't have calendered
they couldn't have calendered	I couldn't have been calendering
you couldn't have been calendering
she couldn't have been calendering
we couldn't have been calendering
you couldn't have been calendering
they couldn't have been calendering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I calender?
could you calender?
could she calender?
could we calender?
could you calender?
could they calender? 	could I be calendering?
could you be calendering?
could she be calendering?
could we be calendering?
could you be calendering?
could they be calendering? 	could I have calendered?
could you have calendered?
could she have calendered?
could we have calendered?
could you have calendered?
could they have calendered? 	could I have been calendering?
could you have been calendering?
could she have been calendering?
could we have been calendering?
could you have been calendering?
could they have been calendering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I calender?
couldn't you calender?
couldn't she calender?
couldn't we calender?
couldn't you calender?
couldn't they calender? 	couldn't I be calendering?
couldn't you be calendering?
couldn't she be calendering?
couldn't we be calendering?
couldn't you be calendering?
couldn't they be calendering? 	couldn't I have calendered?
couldn't you have calendered?
couldn't she have calendered?
couldn't we have calendered?
couldn't you have calendered?
couldn't they have calendered? 	couldn't I have been calendering?
couldn't you have been calendering?
couldn't she have been calendering?
couldn't we have been calendering?
couldn't you have been calendering?
couldn't they have been calendering?