could sub
Verbo regular: sub - subbed- subbed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could sub
you could sub
he could sub
we could sub
you could sub
they could sub 	I could be subbing
you could be subbing
he could be subbing
we could be subbing
you could be subbing
they could be subbing	I could have subbed
you could have subbed
he could have subbed
we could have subbed
you could have subbed
they could have subbed	I could have been subbing
you could have been subbing
he could have been subbing
we could have been subbing
you could have been subbing
they could have been subbing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I couldn't sub
you couldn't sub
he couldn't sub
we couldn't sub
you couldn't sub
they couldn't sub 	I couldn't be subbing
you couldn't be subbing
he couldn't be subbing
we couldn't be subbing
you couldn't be subbing
they couldn't be subbing	I couldn't have subbed
you couldn't have subbed
he couldn't have subbed
we couldn't have subbed
you couldn't have subbed
they couldn't have subbed	I couldn't have been subbing
you couldn't have been subbing
he couldn't have been subbing
we couldn't have been subbing
you couldn't have been subbing
they couldn't have been subbing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I sub?
could you sub?
could he sub?
could we sub?
could you sub?
could they sub? 	could I be subbing?
could you be subbing?
could he be subbing?
could we be subbing?
could you be subbing?
could they be subbing? 	could I have subbed?
could you have subbed?
could he have subbed?
could we have subbed?
could you have subbed?
could they have subbed? 	could I have been subbing?
could you have been subbing?
could he have been subbing?
could we have been subbing?
could you have been subbing?
could they have been subbing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
couldn't I sub?
couldn't you sub?
couldn't he sub?
couldn't we sub?
couldn't you sub?
couldn't they sub? 	couldn't I be subbing?
couldn't you be subbing?
couldn't he be subbing?
couldn't we be subbing?
couldn't you be subbing?
couldn't they be subbing? 	couldn't I have subbed?
couldn't you have subbed?
couldn't he have subbed?
couldn't we have subbed?
couldn't you have subbed?
couldn't they have subbed? 	couldn't I have been subbing?
couldn't you have been subbing?
couldn't he have been subbing?
couldn't we have been subbing?
couldn't you have been subbing?
couldn't they have been subbing?