could button
Verbo regular: button - buttoned- buttoned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could button
you could button
she could button
we could button
you could button
they could button 	I could be buttoning
you could be buttoning
she could be buttoning
we could be buttoning
you could be buttoning
they could be buttoning	I could have buttoned
you could have buttoned
she could have buttoned
we could have buttoned
you could have buttoned
they could have buttoned	I could have been buttoning
you could have been buttoning
she could have been buttoning
we could have been buttoning
you could have been buttoning
they could have been buttoning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't button
you couldn't button
she couldn't button
we couldn't button
you couldn't button
they couldn't button 	I couldn't be buttoning
you couldn't be buttoning
she couldn't be buttoning
we couldn't be buttoning
you couldn't be buttoning
they couldn't be buttoning	I couldn't have buttoned
you couldn't have buttoned
she couldn't have buttoned
we couldn't have buttoned
you couldn't have buttoned
they couldn't have buttoned	I couldn't have been buttoning
you couldn't have been buttoning
she couldn't have been buttoning
we couldn't have been buttoning
you couldn't have been buttoning
they couldn't have been buttoning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I button?
could you button?
could she button?
could we button?
could you button?
could they button? 	could I be buttoning?
could you be buttoning?
could she be buttoning?
could we be buttoning?
could you be buttoning?
could they be buttoning? 	could I have buttoned?
could you have buttoned?
could she have buttoned?
could we have buttoned?
could you have buttoned?
could they have buttoned? 	could I have been buttoning?
could you have been buttoning?
could she have been buttoning?
could we have been buttoning?
could you have been buttoning?
could they have been buttoning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I button?
couldn't you button?
couldn't she button?
couldn't we button?
couldn't you button?
couldn't they button? 	couldn't I be buttoning?
couldn't you be buttoning?
couldn't she be buttoning?
couldn't we be buttoning?
couldn't you be buttoning?
couldn't they be buttoning? 	couldn't I have buttoned?
couldn't you have buttoned?
couldn't she have buttoned?
couldn't we have buttoned?
couldn't you have buttoned?
couldn't they have buttoned? 	couldn't I have been buttoning?
couldn't you have been buttoning?
couldn't she have been buttoning?
couldn't we have been buttoning?
couldn't you have been buttoning?
couldn't they have been buttoning?