could stain
Verbo regular: stain - stained- stained

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could stain
you could stain
she could stain
we could stain
you could stain
they could stain 	I could be staining
you could be staining
she could be staining
we could be staining
you could be staining
they could be staining	I could have stained
you could have stained
she could have stained
we could have stained
you could have stained
they could have stained	I could have been staining
you could have been staining
she could have been staining
we could have been staining
you could have been staining
they could have been staining	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't stain
you couldn't stain
she couldn't stain
we couldn't stain
you couldn't stain
they couldn't stain 	I couldn't be staining
you couldn't be staining
she couldn't be staining
we couldn't be staining
you couldn't be staining
they couldn't be staining	I couldn't have stained
you couldn't have stained
she couldn't have stained
we couldn't have stained
you couldn't have stained
they couldn't have stained	I couldn't have been staining
you couldn't have been staining
she couldn't have been staining
we couldn't have been staining
you couldn't have been staining
they couldn't have been staining	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I stain?
could you stain?
could she stain?
could we stain?
could you stain?
could they stain? 	could I be staining?
could you be staining?
could she be staining?
could we be staining?
could you be staining?
could they be staining? 	could I have stained?
could you have stained?
could she have stained?
could we have stained?
could you have stained?
could they have stained? 	could I have been staining?
could you have been staining?
could she have been staining?
could we have been staining?
could you have been staining?
could they have been staining? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I stain?
couldn't you stain?
couldn't she stain?
couldn't we stain?
couldn't you stain?
couldn't they stain? 	couldn't I be staining?
couldn't you be staining?
couldn't she be staining?
couldn't we be staining?
couldn't you be staining?
couldn't they be staining? 	couldn't I have stained?
couldn't you have stained?
couldn't she have stained?
couldn't we have stained?
couldn't you have stained?
couldn't they have stained? 	couldn't I have been staining?
couldn't you have been staining?
couldn't she have been staining?
couldn't we have been staining?
couldn't you have been staining?
couldn't they have been staining?