could duck
Verbo regular: duck - ducked- ducked

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could duck
you could duck
he could duck
we could duck
you could duck
they could duck 	I could be ducking
you could be ducking
he could be ducking
we could be ducking
you could be ducking
they could be ducking	I could have ducked
you could have ducked
he could have ducked
we could have ducked
you could have ducked
they could have ducked	I could have been ducking
you could have been ducking
he could have been ducking
we could have been ducking
you could have been ducking
they could have been ducking	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not duck
you could not duck
he could not duck
we could not duck
you could not duck
they could not duck 	I could not be ducking
you could not be ducking
he could not be ducking
we could not be ducking
you could not be ducking
they could not be ducking	I could not have ducked
you could not have ducked
he could not have ducked
we could not have ducked
you could not have ducked
they could not have ducked	I could not have been ducking
you could not have been ducking
he could not have been ducking
we could not have been ducking
you could not have been ducking
they could not have been ducking	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I duck?
could you duck?
could he duck?
could we duck?
could you duck?
could they duck? 	could I be ducking?
could you be ducking?
could he be ducking?
could we be ducking?
could you be ducking?
could they be ducking? 	could I have ducked?
could you have ducked?
could he have ducked?
could we have ducked?
could you have ducked?
could they have ducked? 	could I have been ducking?
could you have been ducking?
could he have been ducking?
could we have been ducking?
could you have been ducking?
could they have been ducking? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not duck?
could you not duck?
could he not duck?
could we not duck?
could you not duck?
could they not duck? 	could I not be ducking?
could you not be ducking?
could he not be ducking?
could we not be ducking?
could you not be ducking?
could they not be ducking? 	could I not have ducked?
could you not have ducked?
could he not have ducked?
could we not have ducked?
could you not have ducked?
could they not have ducked? 	could I not have been ducking?
could you not have been ducking?
could he not have been ducking?
could we not have been ducking?
could you not have been ducking?
could they not have been ducking?