could sin
Verbo regular: sin - sinned- sinned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could sin
you could sin
he could sin
we could sin
you could sin
they could sin 	I could be sinning
you could be sinning
he could be sinning
we could be sinning
you could be sinning
they could be sinning	I could have sinned
you could have sinned
he could have sinned
we could have sinned
you could have sinned
they could have sinned	I could have been sinning
you could have been sinning
he could have been sinning
we could have been sinning
you could have been sinning
they could have been sinning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't sin
you couldn't sin
he couldn't sin
we couldn't sin
you couldn't sin
they couldn't sin 	I couldn't be sinning
you couldn't be sinning
he couldn't be sinning
we couldn't be sinning
you couldn't be sinning
they couldn't be sinning	I couldn't have sinned
you couldn't have sinned
he couldn't have sinned
we couldn't have sinned
you couldn't have sinned
they couldn't have sinned	I couldn't have been sinning
you couldn't have been sinning
he couldn't have been sinning
we couldn't have been sinning
you couldn't have been sinning
they couldn't have been sinning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I sin?
could you sin?
could he sin?
could we sin?
could you sin?
could they sin? 	could I be sinning?
could you be sinning?
could he be sinning?
could we be sinning?
could you be sinning?
could they be sinning? 	could I have sinned?
could you have sinned?
could he have sinned?
could we have sinned?
could you have sinned?
could they have sinned? 	could I have been sinning?
could you have been sinning?
could he have been sinning?
could we have been sinning?
could you have been sinning?
could they have been sinning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I sin?
couldn't you sin?
couldn't he sin?
couldn't we sin?
couldn't you sin?
couldn't they sin? 	couldn't I be sinning?
couldn't you be sinning?
couldn't he be sinning?
couldn't we be sinning?
couldn't you be sinning?
couldn't they be sinning? 	couldn't I have sinned?
couldn't you have sinned?
couldn't he have sinned?
couldn't we have sinned?
couldn't you have sinned?
couldn't they have sinned? 	couldn't I have been sinning?
couldn't you have been sinning?
couldn't he have been sinning?
couldn't we have been sinning?
couldn't you have been sinning?
couldn't they have been sinning?