could chair
Verbo regular: chair - chaired- chaired

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't chair
you couldn't chair
he couldn't chair
we couldn't chair
you couldn't chair
they couldn't chair 	I couldn't be chairing
you couldn't be chairing
he couldn't be chairing
we couldn't be chairing
you couldn't be chairing
they couldn't be chairing	I couldn't have chaired
you couldn't have chaired
he couldn't have chaired
we couldn't have chaired
you couldn't have chaired
they couldn't have chaired	I couldn't have been chairing
you couldn't have been chairing
he couldn't have been chairing
we couldn't have been chairing
you couldn't have been chairing
they couldn't have been chairing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
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? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I chair?
couldn't you chair?
couldn't he chair?
couldn't we chair?
couldn't you chair?
couldn't they chair? 	couldn't I be chairing?
couldn't you be chairing?
couldn't he be chairing?
couldn't we be chairing?
couldn't you be chairing?
couldn't they be chairing? 	couldn't I have chaired?
couldn't you have chaired?
couldn't he have chaired?
couldn't we have chaired?
couldn't you have chaired?
couldn't they have chaired? 	couldn't I have been chairing?
couldn't you have been chairing?
couldn't he have been chairing?
couldn't we have been chairing?
couldn't you have been chairing?
couldn't they have been chairing?