could chair
Regular verb: chair - chaired- chaired

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could chair
you could chair
he could chair
we could chair
you could chair
they could chair 	I could be chairing
you could be chairing
he could be chairing
we could be chairing
you could be chairing
they could be chairing	I could have chaired
you could have chaired
he could have chaired
we could have chaired
you could have chaired
they could have chaired	I could have been chairing
you could have been chairing
he could have been chairing
we could have been chairing
you could have been chairing
they could have been chairing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not chair
you could not chair
he could not chair
we could not chair
you could not chair
they could not chair 	I could not be chairing
you could not be chairing
he could not be chairing
we could not be chairing
you could not be chairing
they could not be chairing	I could not have chaired
you could not have chaired
he could not have chaired
we could not have chaired
you could not have chaired
they could not have chaired	I could not have been chairing
you could not have been chairing
he could not have been chairing
we could not have been chairing
you could not have been chairing
they could not have been chairing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I chair?
could you chair?
could he chair?
could we chair?
could you chair?
could they chair? 	could I be chairing?
could you be chairing?
could he be chairing?
could we be chairing?
could you be chairing?
could they be chairing? 	could I have chaired?
could you have chaired?
could he have chaired?
could we have chaired?
could you have chaired?
could they have chaired? 	could I have been chairing?
could you have been chairing?
could he have been chairing?
could we have been chairing?
could you have been chairing?
could they have been chairing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not chair?
could you not chair?
could he not chair?
could we not chair?
could you not chair?
could they not chair? 	could I not be chairing?
could you not be chairing?
could he not be chairing?
could we not be chairing?
could you not be chairing?
could they not be chairing? 	could I not have chaired?
could you not have chaired?
could he not have chaired?
could we not have chaired?
could you not have chaired?
could they not have chaired? 	could I not have been chairing?
could you not have been chairing?
could he not have been chairing?
could we not have been chairing?
could you not have been chairing?
could they not have been chairing?